United States
Department of
Agriculture
Forest Service
Rocky Mountain
Forest and Range
Experiment Station
Water Chemistry of
Rocky Mountain Front Range
Aquatic Ecosystems
Fort Collins,
Colorado 80526
Research Paper
RM-RP-325
Robert C. Musselman
Laura Hudnell
Mark W. Williams
Richard A. Sommerfeld
Musselman, Robert C.; Hudnell, Laura; Williams, Mark W.; Sommerfeld,
Richard A. Water chemistry of Rocky Mountain front range aquatic ecosystems. Res. Pap. RM-RP-325. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 13 p.
Abstract: A study of the water chemistry of Colorado Rocky Mountain
Front Range alpine/subalpine lakes and streams in wilderness ecosystems
was conducted during the summer of 1995 by the USDA Forest Service
Arapaho and Roosevelt National Forests and Rocky Mountain Forest and
Range Experiment Station, and the University of Colorado Institute of
Alpine and Arctic Research. Data were collected to examine the water
chemistry of Front Range high-elevation lakes and their sensitivity to
atmospheric deposition, particularly nitrogen saturation. Water chemistry
data from synoptic surveys of high-elevation lakes in wilderness areas of
other National Forests in Colorado are also included in this report. Because
of the extent, uniqueness, and potential value of the data collected, the
entire water chemistry data base including over 265 samples from more
than 130 lakes and streams is presented. Preliminary data examination
indicates that many lakes have detectible nitrate concentrations, nitrate
concentrations are higher early in the season and decrease as the season
progresses, and inlets often have higher nitrate concentrations than outlets.
Detailed data analysis and interpretation, its relationship to landscape
characteristics, and the implications for ecosystem response and management will be presented by the authors in subsequent manuscripts in
preparation.
Keywords: water chemistry, alpine/subalpine lakes and streams,
atmospheric deposition, nitrogen saturation, ecosystems, aquatic
Cover photo: Upper Lake in Indian Peaks Wilderness
USDA Forest Service
Research Paper RM-RP-325
September 1996
Water Chemistry of
Rocky Mountain Front Range
Aquatic Ecosystems
Robert C. Musselman
Rocky Mountain Forest and Range Experiment Station1
Laura Hudnell
Arapaho and Roosevelt National Forests1
Mark W. Williams
Institute of Arctic and Alpine Research2
Richard A. Sommerfeld
Rocky Mountain Forest and Range Experiment Station1
1
Headquarters is in Fort Collins, Colorado, in cooperation with Colorado State University
2
University of Colorado at Boulder
Contents
Page
Introduction ...................................................................................................
1
Objectives ......................................................................................................
1
Western United States Chemistry ..............................................................
2
Nitrogen Deposition .....................................................................................
2
Nitrogen Saturation ......................................................................................
3
Methods .........................................................................................................
3
Sampling Protocols .................................................................................
4
Analyses ....................................................................................................
4
Results and Discussion ...............................................................................
5
Literature Cited .............................................................................................
6
iii
Water Chemistry of
Rocky Mountain Front Range
Aquatic Ecosystems
Robert C. Musselman, Laura Hudnell,
Mark W. Williams, Richard A. Sommerfeld
may enter storage pools and runoff may result
from the outflow of water from these pools
(Kendall et al. 1995).
This study concentrated on the Front Range of
Colorado. Weber (1976) defines Colorado’s Front
Range as the range of mountains visible when
approaching Denver from the east; specifically,
from Pike’s Peak north along the Continental
Divide through Rocky Mountain National Park.
Others designate the Front Range as the region
from the Colorado and Wyoming border south to
the Arkansas River (Arno and Hammerly 1984).
Although this study included samples from lakes
as far south as the Sangre de Christo Range and
north into the southeastern corner of Wyoming,
the area of study in this report is referenced as the
Front Range.
INTRODUCTION
Aquatic ecosystems are more susceptible and
respond more rapidly to direct input of atmospheric deposition than terrestrial ecosystems
(Irving 1991). Atmospheric deposition in the
Eastern United States and its affect on aquatic
ecosystems are well documented (Irving 1991);
however, little is known about the extent or effects
of atmospheric deposition on lakes and streams in
the Western United States.
Lakes and streams that are most susceptible to
acidic deposition have low concentrations of
anions and cations. This results in low acid neutralizing capacity (ANC) and reduced ability to
buffer acidic input. Low ANC lakes are often
associated with catchments that have little or
poorly developed soils, which reduces soil chemical alteration of precipitation or snowmelt before it
enters lakes and streams. Lakes and streams with
low ANC and catchments with little soil development are often located at high-elevation recently
glaciated sites that have a large percentage of
exposed bedrock. Low ANC also indicates that
reduced amounts of nutrients are available for
aquatic biomass production. Nitrate and phosphate are the nutrients that most frequently limit
productivity; therefore, aquatic ecosystems within
such catchments often have small biomass
amounts.
Snowmelt dominates the hydrologic cycle early
in the melt season. Large concentrations of nitrates
are eluted from the snowpack with the initial melt;
some of this enters surface waters directly. However, unless considerable amounts of bedrock are
exposed, much of the snowmelt enters talus or
soils where biological and chemical alteration
rapidly occurs (Campbell et al. 1995). Snowmelt
OBJECTIVES
This study was a synoptic survey of lake water
chemistry, especially nitrate, in the mountainous
areas east of the Colorado Continental Divide and
in southeastern Wyoming that are exposed to
increasing atmospheric emissions. A goal was to
include as many high-elevation lakes as possible
within a specific sampling time window. For a
subsample of selected catchments in the Arapaho
and Roosevelt National Forests, the study examined differences between lake inlet and outlet
streams, and early season and late season sampling dates. Analyses of relationships between
lake chemistry and landscape characteristics, such
as soil type, geology, vegetation, terrain, watershed size, lake surface area, and elevation, are not
included in this report.
1
tions throughout the season is necessary to determine the interaction between phosphate, nitrate, and
biota, and then decide whether nitrate is exported
because low phosphate levels limit productivity or
because input rates are so high that complete use
is impossible. Excess nitrate in aquatic systems
also occurs from decomposition when populations
decline after phytoplankton blooms, a natural
phenomena occurring during cyclic growth patterns in aquatic systems. Excess nitrate can also
occur in surface waters from a sudden lake turnover after strong wind or heavy precipitation.
Although one source of excess nitrogen is
deposition input, soil and biological processes also
contribute to excess nitrogen in surface waters.
Nitrogen is available from soils but most highelevation sites along Colorado’s Front Range have
relatively young, minimally developed soils;
nitrate availability from these soils is low. Nitrates
in soils are not tightly bound on ion exchange
sites. Nitrogen input in high-elevation ecosystems
with limited soil development is primarily from
atmospheric wet deposition, which is from high
amounts of precipitation. In addition, large
amounts of nitrogen are temporarily stored in the
winter snowpack (Bowman 1992) from wet and
dry deposition and become available for biotic use
with snowmelt.
Although nitrogen input from stream water and
snowmelt is an important source of nitrate for
biomass productivity in high-elevation lakes, there
are alternative sources of nitrate in surface waters.
Monitoring aquatic biomass could explain alternative sources of nitrate in Rocky Mountain aquatic
ecosystems. This information is unavailable from
monitoring water chemistry only. Certain bluegreen algae, such as Anabaena spp and Nostoc spp,
fix nitrogen and add nitrate to the system. Algal
blooms also influence nitrate levels. During these
periods of rapid growth, nitrate concentrations
approach zero as all available nitrate is used.
However, when these populations die, large
amounts of nitrate are released into the water
independent of nitrate input from streamflow or
snowmelt. Stratification or mixing of lakes also
influences the quantity of nitrates available for
phytoplankton growth. This occurs as nitrates at
deeper levels become unavailable to surface algal
populations with stratification or become available
with mixing. Mixing of a stratified lake depends
WESTERN UNITED STATES LAKE CHEMISTRY
Few data are available concerning the current
susceptibility to acidification or nitrogen saturation
of lakes in the Western United States. Only one
major survey of lake susceptibility to acidification
in the Western United States has been conducted
(Eilers et al. 1987, Landers et al. 1987). This onetime sampling identified lakes, generally at high
elevations with poorly developed soils, that might
be susceptible to increases in atmospheric deposition because of their low buffering capacity.
Among the hundreds of lakes sampled in the
1985 survey (Eilers et al. 1987, Landers et al. 1987)
only about 130 were in Colorado and less than a
third of these were from wilderness areas sampled
in the current study. The Front Range urban
corridor of Colorado is experiencing rapid growth
and increased nitrogen and sulfur oxide emissions
that contribute to nitrate and sulfate atmospheric
deposition in the adjacent mountainous areas. In
addition, coal fired power plants in Western
Colorado emit nitrates and sulfates that contribute
to deposition in Front Range ecosystems.
NITROGEN DEPOSITION
Productivity is limited by the amount of nitrate
available for growth in many high-elevation
aquatic ecosystems in the Western United States
(Williams et al. 1996). Nitrate available for growth
and productivity depends upon nitrate input from
deposition, weathering, catchment storage, or
biomass decomposition. Even small changes in the
nitrate levels of aquatic ecosystems can result in
large alterations in species assemblages and phytoplankton abundance. If phytoplankton do not
use all available nitrate to increase productivity,
nitrates are exported and the system is considered
saturated (Williams et al. 1996). However, some
lakes may be phosphate limited due to a low natural
supply of phosphate. Nitrogen export in these
lakes may indicate a lack of phosphate rather than
an excess of nitrogen (Morris and Lewis 1988).
Nitrogen export may represent the seasonal
nature of the ionic pulse of nitrate or the inability
of the biomass to use nitrate when it is rapidly
flushed through the system. Frequent monitoring
of water chemistry and phytoplankton popula2
modifications in above-ground and below-ground
biodiversity as the growth and survival of certain
species are favored over others. Terrestrial ecosystems with sufficient nitrate input can be limited by
other nutrients, such as phosphorus, resulting in
nitrate export. Soils most at risk to increased
nitrogen are those with low: 1) cation exchange
capacity, 2) base saturation, 3) clay or organic
matter content, 4) sulfate and nitrate adsorption
capacity, and those with a pH range of 5.5 to 6.5
(Smith 1992). These are characteristics typical of
high-elevation soils.
Excess nitrogen input from deposition or from
weathering may be historically common at specific
seasonal time periods. However, if the nitrogen
input is higher than historic levels, particularly
during periods of peak seasonal nitrogen use by
biota, ecosystem processes may be altered by the
additional nitrogen.
Recent research indicates that some Colorado
Front Range aquatic ecosystems are near or above
the saturation point for nitrogen deposition (Williams et al. 1993, 1996). High-elevation alpine
aquatic ecosystems are the most susceptible to
excess nitrogen (Baron et al. 1994). Small
catchments with young, shallow soils, large
amounts of exposed, slowly weatherable, quartz or
quartzite bedrock, and steep terrain are particularly susceptible to saturation.
on basin characteristics and lake size and depth,
and can be caused by sudden, local meteorological
changes.
Temporal variation exists in the concentration of
lake nutrients as import and export of nutrients
change. Snowmelt flowpaths and processes,
groundwater storage and retention, weathering,
and soil processes are involved in nitrate concentration changes in surface waters. Interpretation of
water chemistry data must consider naturally
occurring biotic, weathering, or temporal changes
in the nitrate content of lakes and in other possible
sources of nitrogen in surface waters. Excess
nitrate concentrations can also occur without
excess input in Front Range aquatic systems
limited by phosphorus (Morris and Lewis 1988).
Excess nitrogen can have subtle affects before
exportation including increase in productivity or
changes in terrestrial and aquatic species composition. Such changes in ecosystem structure and
function or in ecosystem productivity may be
undesirable if incompatible with management
objectives. These subtle changes are evident only
with long-term, relatively expensive monitoring of
species abundance and biomass in addition to
monitoring water chemistry.
NITROGEN SATURATION
Nitrogen saturation is defined for this report as
the export of nitrogen from the system during
times of the year when ecosystem biota should be
taking up all available nitrogen for growth. Export
indicates that more nitrogen is present in the
system than can be used by the biota; excess
nitrogen is detected in surface waters. This generally occurs during August and early September
(Musselman 1994, Williams 1994) after most
snowmelt has ceased and temperatures are optimum for production. Nitrogen saturation, as
commonly defined, suggests the existence of
maximum possible biota use, which indicates that
growth is not limited by nitrogen. However, as
discussed, other factors can cause export before
the point of maximum productivity is reached.
Nitrogen saturation can have major impacts on
terrestrial ecosystems such as changes in productivity and species composition and increased
winter damage (Aber et al. 1989). There can be
METHODS
High-elevation lakes and first order streams in
catchments with a high percentage of exposed
bedrock or glaciated landscape were selected for
sampling (table 1). Most of the lakes sampled are
in the Arapaho and Roosevelt National Forests
covering the northern part of Colorado’s Front
Range. Some lakes sampled in the Western Lake
Survey (Eilers et al. 1987) were resurveyed.
Lakes were sampled at or near the outlet. Inlet
streams were sampled at a point as near as possible to lake entry. If there was more than one inlet
stream, one was selected in catchments with steep
terrain, few meadows, an abundance of rock
outcrops, and little soil development. These
streams generally had rapid flow through distinct
channels in rocky areas rather than meadows.
They were likely to become nitrogen saturated
3
4
Site Lake or stream
Clear Lake
Kelly Lake
Kelly Lake
Ruby Jewel Lake
Ruby Jewel Lake
Lost Lake South
Lost Lake South Dup
Uneva Pass Lake
Blodgett Lake
Booth Lake
Missouri Lake
Savage Lake (Upper)
Strawberry Lake
Tuhare Lakes
Blue Lake
Blue Lake
Blue Lake *
Blue Lake *
Blue Lake Talus *
Caribou Lake *
Caribou Lake *
Caribou Lake *
Caribou Lake *
Caribou Lake *
Columbine Lake*
Columbine Lake *
Columbine Lake *
Crater Lake
Crater Lake
Crater Lake
Crater Lake
Crater Lake *
Crater Lake *
Dorothy Lake *
Dorothy Lake *
Gourd Lake *
Gourd Lake *
Gourd Lake *
Isabelle Lake *
Island Lake
Island Lake
Island Lake
Island Lake *
Island Lake *
King Lake
King Lake *
King Lake *
King Lake *
Long Lake
Wilderness
Or other location
Colorado State Forest
Colorado State Forest
Colorado State Forest
Colorado State Forest
Colorado State Forest
Eagles Nest
Eagles Nest
Eagles Nest
Holy Cross
Holy Cross
Holy Cross
Holy Cross
Holy Cross
Holy Cross
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Inlet
Inlet
Inlet
Inlet
Outlet
Inlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Inlet
Inlet
Inlet
Outlet
Inlet
Outlet
Inlet
Inlet
Outlet
Inlet
Inlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Inlet
Outlet
Outlet
Outlet
Inlet/
outlet
Table 1. Water chemistry for lakes and streams sampled.
09/11/95
09/10/95
08/02/95
08/01/95
09/09/95
08/25/95
08/25/95
08/25/95
09/04/95
09/25/95
08/06/95
07/18/95
08/26/95
08/07/95
08/04/95
09/04/95
07/11/95
07/11/95
07/11/95
07/31/95
07/31/95
07/31/95
07/31/95
07/31/95
07/31/95
07/31/95
07/31/95
08/07/95
08/07/95
09/16/95
09/16/95
08/11/95
08/11/95
08/07/95
08/07/95
08/19/95
08/19/95
08/19/95
07/08/95
08/11/95
09/07/95
09/07/95
08/19/95
08/19/95
09/17/95
07/24/95
07/24/95
07/24/95
09/10/95
Date
6.91
6.90
6.58
6.63
7.09
6.91
6.62
7.43
6.65
6.54
6.40
5.98
6.78
6.44
5.64
5.95
5.73
6.14
6.98
7.23
6.99
6.99
7.03
7.15
6.89
7.23
7.02
6.08
6.11
6.46
6.43
6.53
6.56
6.24
6.41
7.30
7.23
7.63
6.25
6.44
6.27
6.62
7.09
6.86
6.27
6.05
6.05
6.16
6.58
pH
27.59
18.11
25.09
29.27
37.06
14.51
14.49
56.52
7.02
9.54
11.93
8.81
17.52
11.72
6.82
5.80
6.20
9.20
20.70
25.80
19.03
18.26
16.90
27.40
9.41
21.80
14.70
6.78
8.50
7.88
6.89
10.62
8.10
6.90
6.40
31.80
38.40
55.60
9.40
15.44
9.27
12.15
15.40
10.90
7.62
3.63
4.50
8.58
13.33
240.80
194.80
187.20
228.80
382.80
166.50
166.20
612.30
61.50
103.30
110.50
63.80
110.20
111.60
20.60
23.90
8.12
28.18
130.20
253.83
155.42
144.00
150.07
219.95
79.42
184.98
112.35
41.50
51.70
57.40
57.40
53.29
49.22
19.09
32.46
208.44
171.23
305.07
31.58
119.50
79.10
108.10
121.90
79.13
54.40
18.19
20.93
42.91
129.30
Conduct. ANC
µs/cm µeq/l
198.71
159.09
151.97
184.56
340.38
88.85
86.70
354.09
47.46
66.07
77.27
53.66
282.60
97.26
35.83
30.05
36.73
58.63
174.65
152.89
112.23
118.96
67.61
149.90
59.38
161.88
93.81
42.32
53.44
62.84
63.03
85.43
63.37
34.03
40.92
189.12
268.11
361.63
60.33
95.53
70.35
93.87
124.55
76.70
320.56
23.10
16.92
46.73
114.42
Ca ++
µeq/l
33.73
35.93
41.56
59.88
69.80
46.77
46.37
346.12
11.62
41.88
37.13
22.28
33.91
22.42
6.75
0.00
6.42
9.62
19.25
133.10
58.74
57.01
101.02
88.85
22.29
64.25
36.28
6.75
7.49
6.98
6.17
5.18
6.09
9.38
11.43
96.00
72.97
140.18
9.46
29.36
17.32
25.30
22.13
18.76
20.90
4.36
5.10
14.73
25.02
Mg ++
µeq/l
38.24
24.94
22.46
21.85
37.25
35.41
35.18
35.76
7.69
11.87
9.44
13.68
14.84
9.77
9.40
9.40
11.44
15.05
25.92
21.84
27.93
29.71
4.52
26.10
24.31
20.75
17.88
6.31
7.31
9.22
6.85
8.48
7.79
6.35
6.70
40.71
33.75
51.15
14.31
19.96
10.91
17.23
15.66
12.88
19.23
7.44
16.49
17.96
15.93
Na +
µeq/l
17.52
9.45
8.59
8.30
10.66
7.05
6.80
13.69
2.31
4.65
3.72
4.78
6.72
3.83
2.10
0.00
2.40
3.53
2.25
5.70
7.01
7.01
5.70
6.29
2.92
8.47
5.27
1.25
1.69
1.70
1.08
1.97
1.69
3.17
3.68
7.03
2.66
6.47
4.22
1.37
1.01
1.59
3.25
2.53
3.71
1.13
3.22
4.50
1.45
K+
µeq/l
2.49
1.59
0.89
0.00
2.30
1.35
1.14
1.10
0.00
0.28
0.00
0.00
0.00
1.11
0.67
0.00
1.11
1.55
0.18
0.01
0.00
0.00
0.20
1.03
0.00
0.31
0.28
0.39
0.39
0.00
0.00
0.15
0.53
0.46
1.26
1.07
0.44
0.88
0.61
0.00
0.00
0.99
0.57
0.73
1.05
0.00
2.33
1.17
0.94
NH4+
µeq/l
3.47
2.17
1.40
1.66
1.64
1.41
0.80
1.30
1.55
1.57
0.72
1.30
0.46
2.27
1.60
0.71
1.61
2.20
2.51
1.41
1.68
1.92
0.79
1.52
1.33
2.20
1.61
1.29
1.69
2.68
1.11
1.21
1.27
2.59
2.06
3.05
0.42
1.95
2.00
2.99
0.27
0.85
1.02
0.82
2.06
0.96
1.47
2.62
0.67
Cl µeq/l
1.18
0.00
2.02
15.81
5.00
0.00
0.00
11.71
0.00
0.59
3.71
3.19
5.96
6.37
12.56
7.10
20.85
17.48
17.08
15.26
8.31
13.21
3.73
3.97
3.02
17.95
7.81
5.15
4.05
0.46
0.00
12.71
3.77
8.10
6.69
17.01
0.00
2.50
15.42
8.51
5.85
0.00
4.74
7.73
0.00
1.94
8.34
6.66
0.00
NO3 µeq/l
33.10
26.30
26.22
21.09
33.79
10.76
9.62
42.68
9.40
8.48
15.40
9.47
65.78
18.38
19.56
17.12
20.02
29.85
48.74
17.77
22.75
23.85
3.33
24.73
10.48
17.87
13.06
11.38
14.59
11.46
11.29
13.41
14.12
12.50
14.62
73.70
157.47
198.30
31.52
37.01
14.86
29.16
17.02
14.52
18.05
8.81
6.56
19.35
23.91
SO4 =
µeq/l
5
Site Lake or stream
Long Lake
Lower Coney Lake*
Lower Storm Lake*
Lower Storm Lake *
Lower Storm Lake *
No Name Lake
No Name Lake Dup
Red Deer Lake
Red Deer Lake
Red Deer Lake
Red Deer Lake *
Red Deer Lake *
Red Deer Lake *
Red Deer Lake *
Round Lake
Round Lake
Stone Lake
Stone Lake
Triangle Lake*
Triangle Lake *
Triangle Lake *
Upper Coney Lake*
Upper Coney Lake *
Upper Coney Lake *
Upper Diamond Lake*
Upper Lake
Upper Lake
Upper Lake
Upper Storm Lake*
Watanga Lake
Watanga Lake
Watanga Lake
Watanga Lake
Watanga Lake *
Watanga Lake *
Watanga Lake *
Watanga Area Stream *
U-Shaped Lake
Loveland Pass Stream *
Loveland Pass Stream *
Loveland Pass Stream *
Long Lake
Lost Lake - GLEES
Lost Lake - GLEES
North Twin Lake
South Twin Lake
South Twin Lake
West Glacier Lake - GLEES
West Glacier Lake - GLEES
Wilderness
Or other location
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
Indian Peaks
La Garita
Loveland Pass
Loveland Pass
Loveland Pass
Medicine Bow NF
Medicine Bow NF
Medicine Bow NF
Medicine Bow NF
Medicine Bow NF
Medicine Bow NF
Medicine Bow NF
Medicine Bow NF
Table 1. Cont’d.
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Inlet
Outlet
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Inlet
Inlet
Outlet
Outlet
Outlet
Outlet
Outlet
Inlet
Inlet
Outlet
Inlet
Inlet
Outlet
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Inlet
Outlet
Outlet
Inlet/
outlet
09/10/95
08/03/95
08/07/95
08/07/95
08/07/95
09/17/95
09/17/95
08/07/95
08/07/95
09/10/95
07/27/95
07/27/95
07/27/95
07/27/95
08/03/95
09/04/95
08/07/95
09/03/95
08/11/95
08/11/95
08/12/95
08/03/95
08/03/95
08/03/95
08/07/95
08/08/95
09/03/95
09/03/95
08/07/95
08/10/95
08/10/95
09/14/95
09/14/95
08/20/95
08/20/95
08/20/95
08/20/95
09/19/95
08/02/95
08/02/95
08/02/95
09/18/95
09/18/95
09/18/95
09/18/95
09/18/95
09/18/95
08/11/95
08/11/95
Date
6.54
7.07
6.86
6.57
6.95
6.10
6.09
6.36
6.36
6.40
6.92
6.08
6.63
6.57
5.96
6.22
6.35
6.53
6.18
5.89
6.74
7.00
6.77
6.97
6.99
6.38
6.33
6.27
6.60
6.52
6.51
6.76
6.78
7.57
7.30
7.33
6.93
6.56
7.32
7.02
7.52
6.66
6.52
6.64
7.97
6.84
6.73
5.43
5.96
pH
15.85
17.40
10.90
5.40
9.40
6.19
6.74
10.85
12.58
9.81
28.20
5.94
11.49
11.95
6.85
6.13
10.43
10.50
4.67
3.63
12.75
16.80
9.20
11.70
13.20
14.67
8.42
8.45
9.70
13.22
13.01
15.03
14.30
16.30
15.90
14.40
10.20
12.81
27.70
17.90
32.00
28.78
10.88
7.28
15.50
17.26
12.69
3.40
5.30
147.60
91.31
61.59
38.21
70.20
27.00
27.30
76.80
76.70
80.50
165.51
24.00
68.37
78.29
41.50
47.40
73.60
92.20
26.94
11.13
70.90
116.26
59.62
71.63
82.38
87.90
66.90
49.10
43.93
137.00
128.40
156.10
149.10
120.77
142.79
113.03
65.50
111.20
261.42
116.83
353.47
236.20
78.60
54.00
153.50
193.90
139.00
3.20
34.50
Conduct. ANC
µs/cm µeq/l
139.94
139.42
67.91
41.32
74.00
35.53
34.63
70.11
66.97
76.21
196.06
27.89
74.10
81.59
41.02
37.20
65.42
70.84
30.99
20.66
102.15
161.13
85.58
102.79
76.30
76.50
56.27
61.25
63.12
82.14
73.18
106.39
100.09
90.02
101.15
77.79
64.42
94.16
207.53
101.30
235.93
174.05
70.96
47.31
127.15
156.19
117.51
18.39
33.56
Ca ++
µeq/l
28.18
16.29
27.39
11.43
23.03
12.51
12.34
21.56
21.56
21.47
56.52
8.06
19.25
21.96
12.67
6.25
17.44
13.78
2.88
2.06
6.75
12.42
7.24
8.97
38.25
22.46
6.56
11.68
25.17
23.07
23.96
28.58
27.15
23.28
22.95
21.64
12.18
29.29
80.78
23.77
145.44
106.07
41.64
26.58
34.48
48.06
37.77
5.25
14.72
Mg ++
µeq/l
19.31
16.09
10.27
14.18
14.53
8.53
9.74
18.05
15.31
13.98
31.01
13.96
19.75
18.31
10.44
12.06
10.44
12.02
5.31
2.83
12.74
11.79
10.00
12.14
10.96
11.00
10.64
11.71
8.48
57.14
56.89
0.00
65.25
59.72
56.15
54.02
26.10
30.75
36.89
46.59
21.84
42.71
13.88
10.05
24.27
26.71
19.31
2.77
6.17
Na +
µeq/l
1.64
4.25
3.89
2.28
3.89
2.74
3.04
2.94
3.81
1.23
4.91
1.84
2.53
2.81
4.22
0.00
2.10
0.00
2.86
1.69
3.17
4.09
2.92
3.81
4.19
2.10
0.00
0.00
3.89
1.68
2.76
2.30
1.79
3.09
2.38
2.38
2.22
4.58
8.31
7.19
6.29
8.41
6.47
4.42
16.04
8.75
3.96
0.00
1.45
K+
µeq/l
1.11
1.21
0.00
0.00
0.09
0.00
0.00
0.67
0.67
0.00
0.03
0.00
0.00
0.00
0.39
0.00
0.39
0.00
0.12
0.93
0.09
0.14
0.00
1.27
0.00
0.39
0.00
0.00
0.00
0.84
0.00
4.82
4.70
0.44
1.76
0.01
0.34
0.00
0.55
0.00
0.00
1.33
0.28
0.00
0.44
0.00
0.00
0.00
0.00
NH4+
µeq/l
0.84
2.12
1.97
1.27
1.61
1.96
1.66
2.28
3.24
0.88
2.03
1.38
1.27
1.66
1.17
0.96
1.74
0.00
0.96
1.18
1.35
1.27
1.49
1.64
1.38
0.92
0.32
0.83
1.37
1.19
1.77
1.53
10.64
1.38
1.21
0.96
1.21
4.45
1.72
2.65
2.34
4.22
2.41
2.18
4.19
1.85
0.66
0.90
1.59
Cl µeq/l
0.51
8.82
15.13
5.85
9.48
11.48
11.40
4.14
3.58
0.00
13.19
6.56
6.55
5.79
6.62
1.13
3.13
0.99
9.55
8.74
16.34
15.16
12.40
9.48
16.18
4.77
0.91
1.97
20.05
0.26
0.00
0.00
0.00
2.45
0.00
0.00
4.52
3.07
4.92
7.84
2.44
0.67
0.99
0.00
0.00
0.00
0.00
7.23
0.00
NO3 µeq/l
32.78
49.91
14.25
14.06
16.48
8.74
9.30
25.01
25.05
23.50
71.59
11.33
25.54
25.91
12.16
12.10
17.07
19.17
5.60
5.17
20.73
39.85
25.14
36.45
14.41
20.37
15.73
15.82
15.39
12.01
13.01
16.59
21.03
16.37
12.48
14.14
16.18
19.86
43.20
15.87
13.41
19.59
33.63
18.55
22.34
14.12
11.34
4.92
10.20
SO4 =
µeq/l
6
Site Lake or stream
West Glacier Lake - GLEES
West Glacier Lake - GLEES
Abyss Lake
Abyss Lake
Abyss Lake
Abyss Lake Dup
Chicago Lake*
Chicago Lake *
Chicago Lake *
Frozen Lake
Frozen Lake
Frozen Lake
North Lake
North Lake
South Lake
South Lake
South Lake Dup
Summit Lake*
Summit Lake *
Upper Middle Beartrack Lake
Upper Middle Beartrack Lake Dup
Upper Middle BeartracksLake
Long Lake Valley Stream *
Long Lake Valley Stream *
Long Lake Valley Stream *
Long Lake Valley Stream *
Niwot *
Niwot *
Niwot *
Niwot *
Niwot *
Blue Lake
Blue Lake
Blue Lake
Camp Lake
Camp Lake
Carey Lake
Carey Lake
Carey Lake
Carey Lake Area Inlet Stream *
Carey Lake Area Inlet Stream *
Carey Lake Area Inlet Stream *
Carey Lake Area Inlet Stream *
Hang Lake
Hang Lake
Hang Lake
Iceberg Lake
Iceberg Lake
Island Lake
Wilderness
Or other location
Medicine Bow NF
Medicine Bow NF
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Mount Evans
Niwot Ridge
Niwot Ridge
Niwot Ridge
Niwot Ridge
Niwot Ridge
Niwot Ridge
Niwot Ridge
Niwot Ridge
Niwot Ridge
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Table 1. Cont’d.
Outlet
Inlet
Outlet
Outlet
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Inlet
Outlet
Inlet
Outlet
Inlet/
outlet
09/14/95
09/14/95
08/04/95
09/13/95
10/04/95
10/04/95
08/02/95
08/02/95
08/02/95
08/04/95
09/13/95
10/05/95
08/07/95
09/13/95
08/07/95
09/13/95
09/13/95
08/02/95
08/02/95
09/10/95
09/10/95
08/05/95
07/08/95
07/08/95
07/08/95
07/08/95
07/07/95
07/07/95
07/07/95
07/07/95
07/07/95
08/02/95
09/08/95
09/08/95
09/10/95
09/10/95
08/06/95
09/16/95
09/16/95
08/15/95
08/15/95
08/15/95
08/15/95
08/02/95
09/08/95
09/08/95
08/06/95
09/17/95
08/06/95
Date
5.50
6.22
6.73
6.83
6.42
6.43
7.04
6.73
7.08
6.34
6.54
6.43
6.33
6.56
6.21
6.55
6.63
6.86
6.89
6.32
6.06
6.45
6.54
6.33
6.69
6.80
6.00
6.39
6.01
6.20
6.12
6.51
6.65
6.71
6.55
6.60
6.40
6.51
6.70
7.34
5.99
6.49
5.55
6.39
6.55
6.56
6.04
6.71
6.21
pH
2.82
5.03
12.70
11.97
12.12
12.81
28.60
15.50
24.10
11.92
11.53
11.66
12.37
13.33
9.83
18.46
18.65
14.10
14.64
9.57
9.23
9.58
21.30
20.90
13.40
17.80
12.58
7.92
5.30
19.80
8.72
18.74
17.45
17.73
16.33
17.50
12.04
8.39
11.65
17.00
2.40
5.30
2.20
18.46
12.67
12.92
9.25
7.33
9.86
4.40
39.90
101.90
91.30
95.90
97.50
164.29
81.69
151.18
94.20
97.60
100.80
113.40
111.30
65.90
117.00
118.20
82.46
97.75
59.60
56.70
67.60
125.48
125.98
95.81
88.01
66.62
36.40
63.23
65.56
75.56
160.00
180.60
185.40
168.60
179.90
94.00
84.00
120.40
163.04
18.39
41.55
12.87
114.70
131.50
131.30
44.40
53.60
67.60
Conduct. ANC
µs/cm µeq/l
9.03
35.78
89.17
93.43
94.65
83.79
200.05
115.52
194.06
90.82
97.50
88.53
105.59
138.02
79.24
159.64
162.22
95.31
104.29
55.85
54.75
65.77
186.98
147.41
117.86
134.88
70.61
45.76
32.53
128.14
63.82
123.35
138.24
141.84
129.07
137.12
79.74
81.74
106.36
167.56
14.47
40.62
4.84
99.80
107.42
105.86
52.06
56.58
60.83
Ca ++
µeq/l
4.44
15.63
17.03
13.82
13.98
12.70
43.02
16.78
34.14
20.90
18.25
17.37
27.90
28.73
20.00
33.39
33.60
27.81
20.57
19.69
19.64
25.18
33.23
24.76
16.62
14.40
23.28
9.79
11.19
35.54
19.58
36.80
34.35
35.23
30.46
32.22
17.44
12.77
19.64
26.08
2.39
6.25
1.40
20.52
18.10
17.65
8.89
9.05
11.19
Mg ++
µeq/l
2.96
7.57
16.96
19.72
20.51
21.62
36.15
15.01
27.93
10.79
13.17
13.33
11.83
1.15
6.70
13.26
13.24
21.44
25.75
13.33
14.38
13.09
48.02
15.40
20.14
24.49
41.89
11.44
13.96
50.50
15.40
32.32
38.33
39.48
46.42
48.26
13.40
11.11
16.61
18.44
3.87
4.22
6.00
20.93
24.91
24.78
12.88
14.14
10.18
Na +
µeq/l
2.15
1.92
8.08
7.16
7.09
7.46
9.64
8.75
12.84
7.21
6.66
6.07
3.79
0.00
6.37
8.85
8.88
7.60
10.20
14.86
15.39
14.96
7.60
9.28
7.60
8.00
9.69
2.81
6.19
11.53
9.41
6.61
7.25
7.55
6.73
6.37
5.06
4.91
4.74
6.85
1.97
1.53
0.79
4.11
5.03
4.97
3.81
3.18
5.50
K+
µeq/l
0.00
1.11
0.39
0.87
0.00
0.00
0.30
0.00
1.31
0.00
0.00
0.00
1.39
0.00
0.00
0.00
0.00
0.00
0.56
1.03
0.00
0.22
0.65
0.60
0.86
0.33
0.19
1.93
1.78
0.01
0.41
0.00
2.30
2.38
3.20
3.28
0.67
0.00
0.00
0.00
0.04
0.00
0.34
0.00
1.40
1.42
0.67
0.00
0.67
NH4+
µeq/l
0.61
1.27
3.14
2.96
3.12
4.31
1.89
2.26
3.33
2.13
2.63
1.91
10.13
1.77
2.04
3.54
3.57
1.89
3.07
4.30
6.17
3.85
4.68
3.38
3.75
3.41
3.95
1.64
1.97
11.59
2.12
2.27
1.70
1.80
2.23
1.53
1.86
0.00
0.00
1.38
2.37
1.35
1.02
1.97
1.14
1.04
1.92
0.00
3.75
Cl µeq/l
6.25
0.00
10.04
7.00
5.69
5.82
12.87
23.24
8.95
12.56
6.12
4.78
0.31
0.24
16.21
41.40
38.46
14.34
4.44
0.00
0.00
0.36
11.68
1.68
16.17
14.77
0.00
11.16
6.06
0.00
4.10
6.28
1.60
1.13
0.00
0.00
13.82
2.99
1.54
16.08
4.37
11.82
2.98
6.80
0.57
0.27
16.97
8.04
6.64
NO3 µeq/l
4.42
10.75
26.27
28.84
31.49
32.38
58.16
31.95
56.76
16.35
18.35
20.69
18.61
26.95
15.95
40.55
40.55
20.18
29.81
17.08
17.30
14.85
94.98
52.97
26.38
44.53
44.70
9.60
6.71
77.72
7.87
24.68
23.33
26.03
18.37
17.76
13.67
12.94
12.71
13.52
2.37
5.50
1.65
15.18
14.13
14.05
14.17
13.77
15.33
SO4 =
µeq/l
7
Site Lake or stream
Island Lake
Island Lake Dup
Little Rainbow Lake*
Little Rainbow Lake*
Lost Lake
Lost Lake
Lower Camp Lake
Lower Sandbar Lake
Lower Sandbar Lake
Lower Sandbar Lake
Lower Twin Crater Lake
Lower Twin Crater Lake
Lower Twin Crater Lake
Lower Twin Crater Lake
Lower Twin Crater Lake
Lower Twin Crater Lake
McIntyre Lake
McIntyre Lake
McIntyre Lake
Number 1 Lake
Number 1 Lake
Number 1 Lake
Number 2 Lake
Number 2 Lake
Number 2 Lake
Number 3 Lake
Number 3 Lake
Number 3 Lake
Number 3 Lake*
Number 3 Lake*
Number 4 Lake
Number 4 Lake
Number 4 Lake
Number 4 Lake Dup
Number 4 Lake*
Number 4 Lake*
Number 4 Lake*
Rocky Hole Lake*
Sugarbowl Lake
Sugarbowl Lake
Twin Crater Lake*
Twin Crater Lake*
Upper Camp Lake
Upper Camp Lake
Upper Sandbar Lake
Upper Sandbar Lake
Upper Twin Crater Lake
Upper Twin Crater Lake
Upper Twin Lake
Wilderness
Or other location
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Rawah
Table 1. Cont’d.
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Outlet
Inlet
Outlet
Inlet
Inlet
Outlet
Inlet
Outlet
Outlet
Inlet
Inlet
Inlet
Outlet
Outlet
Outlet
Inlet
Inlet
Outlet
Outlet
Outlet
Outlet
Outlet
Outlet
Inlet
Inlet
Outlet
Outlet
Outlet
Outlet
Inlet
Outlet
Inlet/
outlet
09/16/95
08/06/95
08/16/95
08/16/95
08/06/95
09/09/95
08/13/95
08/06/95
09/15/95
09/15/95
08/06/95
09/16/95
09/16/95
08/06/95
09/17/95
09/17/95
08/06/95
09/17/95
09/17/95
08/06/95
09/15/95
09/15/95
08/06/95
09/15/95
09/15/95
08/05/95
09/15/95
09/15/95
08/16/95
08/16/95
08/05/95
08/15/95
09/15/95
08/05/95
08/16/95
08/16/95
08/16/95
08/15/95
08/06/95
09/17/95
08/15/95
08/15/95
08/13/95
09/10/95
08/06/95
09/15/95
08/06/95
09/16/95
08/06/95
Date
6.67
6.22
7.00
6.97
6.44
6.59
6.63
6.48
6.90
6.88
6.36
6.65
6.63
6.95
6.70
6.84
6.43
6.53
6.58
6.36
6.44
6.56
6.28
6.55
6.76
6.31
6.43
6.55
6.83
6.75
5.99
7.21
6.37
5.97
6.24
6.91
7.01
7.22
6.46
6.61
6.95
6.83
6.55
6.52
6.80
6.93
6.30
6.68
6.91
pH
7.52
9.45
13.00
10.50
18.25
19.02
16.24
15.11
16.92
16.19
12.58
11.52
11.02
17.24
17.05
18.16
12.08
11.28
11.77
11.25
9.31
10.90
10.72
9.10
8.97
10.37
8.97
8.99
9.20
7.70
9.08
18.71
7.56
9.94
4.90
11.00
14.90
20.40
11.16
10.08
10.40
9.30
14.13
13.04
14.56
18.25
13.83
11.60
12.82
70.00
67.70
120.57
74.92
137.30
173.90
158.10
139.60
192.50
181.00
94.00
110.30
108.80
166.10
184.40
198.20
103.70
113.80
118.00
95.00
86.40
103.90
82.90
86.80
84.80
77.10
73.00
84.60
61.80
65.55
45.30
137.33
47.30
43.50
14.75
81.47
108.56
171.36
96.80
100.10
80.32
82.66
124.70
125.90
136.80
200.00
104.30
110.60
120.50
Conduct. ANC
µs/cm µeq/l
60.81
59.33
103.39
64.42
103.84
127.50
108.44
95.01
147.77
139.69
79.74
99.81
93.84
105.64
133.05
143.49
56.39
87.29
93.81
65.42
71.07
79.59
65.42
70.19
66.61
60.83
65.41
61.06
68.86
56.64
50.60
159.18
53.75
49.20
22.75
59.53
95.31
173.65
66.97
77.97
58.03
74.00
93.40
98.99
98.50
153.79
93.26
100.65
88.12
Ca ++
µeq/l
9.25
10.37
18.92
16.12
41.80
43.69
29.38
26.66
33.24
32.27
15.88
16.46
15.70
33.74
32.15
36.64
15.88
17.72
21.88
20.74
18.11
20.19
20.74
17.59
17.42
19.91
15.79
16.00
6.91
11.93
9.63
11.11
8.94
9.63
3.04
14.81
16.45
20.65
15.06
14.70
15.96
13.57
22.67
20.72
26.66
34.39
18.27
16.38
18.27
Mg ++
µeq/l
8.83
8.87
37.93
28.53
51.89
93.87
39.91
31.71
43.65
42.65
18.88
21.04
21.34
49.80
60.16
89.30
26.79
34.63
34.79
23.97
20.34
24.72
19.44
19.67
20.14
17.79
18.77
18.62
16.70
20.18
13.40
23.75
12.06
12.61
3.13
37.93
38.63
31.93
25.66
28.32
26.92
10.27
33.77
36.97
31.71
44.39
21.14
21.02
32.28
Na +
µeq/l
4.74
5.50
5.58
3.25
5.91
4.72
6.67
6.78
8.70
7.46
6.34
6.49
6.35
4.65
7.71
7.60
5.06
6.98
6.10
6.78
6.02
5.93
6.78
6.10
6.15
7.19
7.22
6.15
4.42
4.86
6.78
9.95
5.33
6.34
3.25
7.03
9.39
10.08
6.78
7.12
7.14
5.37
7.17
6.42
7.19
8.70
7.62
6.58
6.34
K+
µeq/l
0.00
0.39
0.00
0.86
1.55
6.20
0.00
0.67
2.46
2.36
0.39
0.89
0.88
1.22
4.02
4.50
0.94
1.71
1.65
0.67
0.92
1.17
0.67
0.85
0.86
0.67
0.00
0.00
0.44
0.00
1.22
0.44
0.00
0.94
2.05
0.16
1.01
0.07
0.67
1.32
0.27
0.63
0.00
2.38
0.67
2.44
1.22
0.91
0.67
NH4+
µeq/l
0.00
2.67
1.41
1.38
4.94
1.99
2.12
1.49
1.24
0.96
2.16
0.00
0.00
3.33
0.00
0.00
2.91
0.00
0.00
2.31
0.00
0.00
3.76
0.00
0.00
2.27
0.00
0.00
0.34
1.33
3.61
2.06
0.00
2.54
0.96
1.49
1.13
4.33
3.04
0.00
1.61
1.04
3.84
2.28
1.94
1.14
2.26
0.00
2.06
Cl µeq/l
0.00
6.07
5.40
6.82
0.00
0.00
0.00
0.59
0.00
0.00
12.75
4.37
0.00
0.00
0.00
0.00
0.00
0.38
0.00
4.59
0.47
0.54
6.32
1.06
0.28
8.48
9.63
0.83
2.26
9.66
17.72
16.45
13.37
17.46
8.50
11.71
8.58
13.52
4.61
0.58
7.37
12.19
0.00
0.00
1.64
0.00
15.93
4.23
0.00
NO3 µeq/l
11.18
11.37
11.64
11.79
29.15
28.63
17.84
15.29
15.60
15.16
18.86
17.97
18.13
24.17
24.77
24.33
15.85
14.38
14.79
15.16
15.19
15.32
15.53
14.70
15.18
14.85
16.82
17.86
16.33
12.50
16.19
15.83
15.58
15.03
4.65
16.29
15.00
17.52
13.53
12.31
9.85
10.56
18.95
30.99
14.84
15.16
19.95
18.22
19.64
SO4 =
µeq/l
8
Upper Twin Lake
Inlet
Upper Twin Lake
Outlet
Banjo Lake
Banjo Lake Dup
Commanche Lake
Cotton Lake
Crater Lake
Deadman Lake
Dry Lake Upper
Dry Lake Upper Dup
Elaine Lake
Eureka Lake
Glacier Lake
Goodwin Lake
Hermit Lake
Horn Lake
Horseshoe Lake
Hunts Lake
Hunts Lake Dup
Lilly Lake
Lilly Lake Dup
Lost Lake
Lost Lake Dup
Lower Brush Lake
Lower Bushnell Lake
Lower Little Sand Cr. Lake
Lower Sand Creek Lake
Macey Lake Middle
Macey Lake Upper
Mas Alto Lake
Medano Lake
Megan Lake
North Colony Lake
North Colony Lake Dup
North Colony Lake Upper
North Crestone Lake
Rito Alto Lake
San Isabel Lake
Silver Lake
Small Lake Above U-Shaped Lake
Small Lake N of Medano
Small Lake S of Blue Lake
South Branch Lake
South Colony Lake
South Crestone Lake
Stout Creek Lake (Upper)
Stuart Creek Lake (Lower)
U-Shaped Lake
Unnamed Above Lilly Lake
Rawah
Rawah
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Inlet/
outlet
Site Lake or stream
Wilderness
Or other location
Table 1. Cont’d.
09/17/95
09/17/95
08/02/95
08/02/95
07/25/95
07/31/95
07/31/95
08/03/95
07/25/95
07/25/95
07/28/95
07/25/95
08/02/95
07/26/95
07/25/95
07/26/95
07/25/95
07/28/95
07/28/95
07/25/95
07/25/95
08/02/95
08/02/95
08/01/95
08/02/95
08/03/95
07/25/95
07/25/95
07/25/95
07/28/95
07/27/95
07/25/95
07/25/95
07/25/95
07/25/95
07/27/95
07/28/95
07/27/95
08/02/95
08/03/95
07/27/95
08/02/95
08/01/95
07/27/95
07/26/95
08/01/95
08/01/95
08/03/95
07/25/95
Date
6.59
6.82
6.53
6.56
7.21
7.56
6.46
6.63
6.88
6.90
6.80
7.14
6.67
7.17
7.24
6.94
7.19
6.89
6.92
7.01
7.02
6.83
6.82
7.48
7.35
6.62
6.56
6.95
6.89
6.34
6.62
6.97
6.87
6.94
7.08
7.06
6.79
6.93
6.63
6.26
6.57
6.14
7.09
7.29
6.97
6.29
6.57
6.34
7.03
pH
12.46
12.38
14.63
15.76
62.55
162.00
16.57
27.01
51.19
50.45
27.17
74.45
8.37
108.86
118.73
38.44
78.91
43.45
42.02
53.42
53.42
30.50
30.40
70.18
31.42
18.35
18.04
40.04
49.91
8.65
29.68
58.20
82.31
82.20
79.12
45.91
26.56
39.90
28.15
7.29
26.01
3.41
66.30
50.76
40.50
11.41
18.58
9.30
49.81
120.20
121.50
135.20
136.40
556.90
1048.50
128.30
206.50
502.20
493.60
248.90
554.80
79.70
612.10
761.20
388.10
620.60
376.70
374.10
467.50
469.90
272.80
271.70
673.90
267.00
153.40
148.60
407.30
381.70
66.30
229.60
447.60
572.90
569.10
757.80
467.40
224.20
391.40
213.20
53.70
194.50
19.80
654.10
418.70
406.20
77.80
152.30
75.00
466.70
Conduct. ANC
µs/cm µeq/l
101.06
100.76
75.82
113.17
426.15
1361.68
136.35
210.85
424.20
411.33
196.19
636.73
47.63
1127.66
364.20
10.66
472.55
325.80
323.97
11.45
524.95
231.16
227.88
598.80
177.84
131.28
137.42
378.59
354.09
57.88
190.08
47.16
613.77
1068.09
365.74
438.06
169.99
348.24
171.43
37.36
144.05
9.48
558.88
389.62
367.65
78.83
123.40
45.16
575.85
Ca ++
µeq/l
18.41
18.18
19.96
9.95
196.50
611.36
11.80
16.90
109.03
108.78
17.40
222.67
8.50
273.64
23.16
9.39
214.77
73.29
72.73
11.10
46.74
24.41
23.69
87.97
98.50
18.49
21.20
40.07
106.64
10.40
35.08
44.19
356.31
363.71
71.61
54.89
29.54
31.55
46.29
9.78
34.46
0.00
87.71
114.63
32.46
20.78
31.74
14.36
33.82
Mg ++
µeq/l
36.88
36.99
12.06
18.44
36.32
37.39
4.72
22.89
49.28
28.49
16.73
24.32
11.85
47.23
9.25
3.11
36.97
29.75
22.37
8.99
20.57
13.86
14.50
33.20
11.35
19.96
18.59
18.31
17.96
8.48
25.75
93.04
39.15
33.67
12.02
26.08
16.83
19.34
24.64
8.90
37.04
3.30
62.28
42.98
16.77
12.17
15.23
14.86
17.96
Na +
µeq/l
6.13
6.12
5.91
6.69
9.69
8.51
1.22
2.62
10.79
6.85
2.50
9.69
5.16
23.95
0.46
0.26
10.13
11.29
8.37
0.50
9.49
2.78
3.03
21.04
6.26
3.42
7.87
6.19
5.32
0.52
6.24
12.07
19.44
10.56
7.24
3.06
2.19
2.51
5.49
0.00
5.58
0.86
10.04
15.78
2.26
6.02
8.46
0.95
10.13
K+
µeq/l
1.85
1.82
0.00
2.45
1.11
2.54
0.00
0.96
2.66
1.44
2.04
1.11
0.00
0.55
0.00
0.00
0.83
1.00
0.00
0.00
2.16
0.98
0.00
1.25
0.00
1.35
0.00
2.00
0.83
0.00
0.00
26.50
15.52
1.72
0.89
1.11
0.00
0.95
0.98
0.00
0.00
0.00
1.29
2.00
4.99
0.00
0.87
0.00
2.00
NH4+
µeq/l
0.00
0.00
7.44
11.86
3.44
5.68
1.38
4.78
13.48
3.92
2.78
2.64
2.01
4.12
3.70
1.13
3.13
9.44
2.18
4.21
5.36
0.52
0.92
10.23
1.95
2.81
3.51
2.40
2.96
0.96
2.28
2.96
14.61
3.38
2.26
2.60
1.27
2.20
1.61
1.97
2.23
0.70
22.54
12.69
1.59
3.29
3.13
1.88
3.81
Cl µeq/l
0.00
0.00
7.82
7.70
5.59
28.92
16.70
2.94
11.52
10.24
0.94
21.21
0.35
17.03
6.48
4.98
13.02
18.40
18.53
12.91
9.24
3.86
3.88
0.41
5.53
0.00
5.00
0.95
12.02
10.98
17.11
6.98
21.55
21.93
15.03
5.23
5.77
4.38
7.92
0.00
3.21
1.59
0.00
11.80
0.28
9.73
5.36
0.00
17.19
NO3 µeq/l
19.55
19.71
6.21
9.06
112.73
176.40
25.29
45.77
36.77
31.81
13.35
258.03
11.02
562.79
526.77
16.80
231.94
27.21
27.20
89.30
86.49
11.64
11.94
68.35
21.22
44.66
26.82
16.80
125.55
12.69
20.17
182.31
318.14
282.33
139.23
17.23
13.88
10.80
26.97
8.34
22.18
4.95
25.56
73.77
12.24
17.72
30.51
10.49
43.47
SO4 =
µeq/l
9
Upper Brush Lake
Upper Bushnell Lake
Upper Lake of The Clouds
Upper Lake of The Clouds Dup
Upper Little Sand Creek Lake
Upper Sand Creek Lake
Upper Willow Lake
Venable Lake Lower
Venable Lake Upper
West Creek Lake
Wild Cherry Lake
Wild Cherry Lake Dup
Glacier Lake
Small Lake S. of Blue Lake
Small Lake S. of Blue Lake
Lake Due South of Ute
Lake Due South of Ute
Lake Due South of Ute - Dup
Middle Ute Lake
Middle Ute Lake
Small Pond Above Trout Lake
Small Pond Above Trout Lake
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
Sangre De Cristo
South San Juan
South San Juan
South San Juan
Weminuche
Weminuche
Weminuche
Weminuche
Weminuche
Weminuche
Weminuche
Inlet/
outlet
* water analysis by UC, all others analyzed by USFS, RMS Lab
Detection Limits, USFS, RMS Lab:
Site Lake or stream
Wilderness
Or other location
Table 1. Cont’d.
08/01/95
08/02/95
07/26/95
07/26/95
08/03/95
07/25/95
07/26/95
07/25/95
07/25/95
08/01/95
07/25/95
07/25/95
09/05/95
09/05/95
09/05/95
08/05/95
09/13/95
08/05/95
08/08/95
09/13/95
08/05/95
08/11/95
Date
7.11
6.79
7.26
7.53
6.47
7.01
6.73
6.79
6.74
6.25
7.01
7.05
6.34
5.90
6.04
5.94
5.90
6.29
6.12
6.21
6.20
6.08
pH
74.97
12.25
121.49
120.01
13.43
28.18
27.27
33.24
36.85
12.42
49.66
50.38
7.52
4.16
4.01
5.30
4.88
5.36
6.81
7.94
3.64
4.79
747.60
78.50
787.40
789.40
110.10
195.10
223.40
267.50
313.70
65.80
440.00
445.00
65.30
26.20
26.80
31.30
19.60
32.20
43.80
41.90
24.10
26.90
Conduct. ANC
µs/cm µeq/l
0.680
346.86
80.72
1034.93
1043.91
108.06
187.36
184.07
188.82
227.69
61.92
434.79
428.05
55.64
21.86
20.39
33.40
33.53
33.11
44.11
43.71
19.47
23.60
Ca ++
µeq/l
0.353
64.63
23.44
325.04
329.15
12.31
25.78
31.52
84.67
105.33
25.07
93.23
92.62
9.21
3.04
2.83
13.99
9.55
14.02
21.16
18.19
7.55
7.32
Mg ++
µeq/l
0.281
27.57
11.58
35.97
34.80
13.87
17.19
7.76
46.32
39.97
25.56
22.43
22.77
12.48
6.44
6.57
4.11
16.66
5.75
5.45
8.31
3.41
9.40
Na +
µeq/l
0.256
11.47
6.85
8.80
9.90
1.98
5.80
1.03
19.72
12.30
9.64
5.99
6.31
6.07
3.91
4.02
3.29
7.08
10.26
1.95
1.46
2.13
4.27
K+
µeq/l
0.674
0.92
3.05
1.11
8.87
0.00
1.03
0.00
4.10
2.94
1.15
2.15
2.92
0.00
0.00
0.00
0.00
0.61
0.00
0.00
3.55
0.00
0.00
NH4+
µeq/l
0.402
3.53
3.72
4.26
3.38
3.73
2.97
1.41
19.41
8.72
9.18
1.97
2.27
0.78
0.00
0.00
18.79
2.18
56.88
9.54
2.08
1.55
2.16
Cl µeq/l
0.244
0.73
11.14
4.98
11.77
10.53
4.58
16.43
0.00
2.97
10.35
0.49
0.50
0.00
0.00
0.00
0.00
0.59
0.00
0.00
4.28
0.00
0.61
NO3 µeq/l
0.373
80.14
21.19
526.77
519.69
26.49
37.02
11.57
40.29
52.53
26.04
84.89
83.99
10.24
5.98
6.21
7.82
10.12
8.23
15.24
17.28
2.75
7.50
SO4 =
µeq/l
Samples were collected in 250 ml brown plastic
bottles that were prewashed and filled with deionized water. They were emptied just before sampling. The bottles were labeled onsite using permanent markers with sample location, date, time,
crew member names, and whether a lake or
stream was sampled. Lake samples were collected
as far from the shore as possible without disturbing the lake bottom. Stream samples were collected slightly upstream from the stream outlet as
far into the stream as possible or at midstream if
the stream was narrow. Bottles were rinsed three
times with sample water then filled completely
and capped. The samples were immediately
placed in a small Styrofoam or thermal cooler
containing a frozen icepack to keep them cold
during transport. Protocols called for the collection
of one duplicate sample from every 10th site and
one deionized water field blank from every 20th
site. Field blanks were unused, unemptied sample
bottles taken to the field and returned unopened
for analysis. Lakes chosen for duplicate samples
were selected at random. Color photos were taken
of the sample collection site and the surrounding
landscape. A field data sheet containing lake,
stream, watershed, and weather information was
completed on site. Samples and field data sheets
were shipped by overnight mail or hand delivered
to the Rocky Mountain Forest and Range Experiment Station laboratory for chemical analysis.
University of Colorado samples were analyzed in
their laboratory.
because of limited opportunity for contact with
soils of sufficient exchange capacity to retain
nitrates.
The lakes and streams in the Rawah and Indian
Peaks Wilderness areas were sampled for water
chemistry in late July or early August. A second
sample was collected in early September. If the
system had detectible levels of nitrate in any of the
samples, it was considered nitrogen saturated.
Although this study was a synoptic survey of
lakes in Indian Peaks and Rawah Wilderness
areas, data from additional lakes sampled during
1995 using the same protocols and the same
sample collection window are also included in this
report. These additional lakes are: five lakes in the
Medicine Bow National Forest in southeastern
Wyoming; 45 lakes and streams studied by the
University of Colorado in the Indian Peaks and
Rawah Wilderness areas in the Arapaho and
Roosevelt National Forests; and approximately 80
lakes surveyed as synoptic or long-term monitoring in the Sangre De Cristo, Mt. Evans,
Weminuche, South San Juan, La Garita, and Holy
Cross Wildernesses in Colorado.
Sampling protocols
Sample collection followed precise protocols to
avoid contamination and to standardize where and
how samples were collected. Two training sessions
were held before sampling to instruct field crews
on the proper procedures. One lake water sample
was collected from each site. An inlet-stream water
sample was also collected if suitable inlets were
present and access was possible for the Rawah
Wilderness, Indian Peaks Wilderness, and Medicine Bow Mountain range lakes. The first sample
was collected near the lake outlet and the second
from a first order stream inlet to the lake. The
sampling point was on the lake or stream edge on
solid ground or rock to minimize water disturbance. Areas of wet or bog-type soil where foot
pressure might disturb the lake or stream water
were avoided. It was very important not to disturb
the lake or stream bottom to avoid sample contamination. Plastic gloves, prewashed in distilled
water, dried, and stored in zipped plastic bags,
were worn during sample collection.
Analyses
Samples were filtered (0.045 mm) in the laboratory and analyzed for cations (Ca2+, Mg2+, Na+, K+,
NH4+) and anions (Cl-, NO3-, SO42-, PO43-) using ion
chromatography. Sample pH, alkalinity, and
conductivity were also determined in the laboratory. Data were examined for any unusual outlier
of anions, cations, pH, alkalinity, or conductivity,
and for ionic balances. A sample was considered
nitrogen saturated if the nitrate concentration was
0.244 µeq/l or higher, which was the detection
limit for the laboratory analytical methods at the
Rocky Mountain Forest and Range Experiment
Station laboratory.
10
RESULTS AND DISCUSSION
This study provides the most extensive database
in existence regarding the chemical composition of
high-elevation lakes and streams in the Front
Range of the Rocky Mountains of Colorado and
southeastern Wyoming (table 1). In addition, this
study identifies lakes that might be susceptible to
acidification and/or nitrogen loading from atmospheric deposition. The data presented here will be
analyzed further to relate surface water chemistry
to landscape characteristics. Lakes with very low
ANC and high levels of nitrate will be further
examined in follow up studies.
Most lakes examined in this study had low
ANC (figure 1), suggesting sensitivity to acidification. More than 10% of the lakes were below 50
µeq/l ANC and can be considered very sensitive.
The Sangre de Cristo Wilderness, where more than
two-thirds of the lakes had greater than 200 µeq/l
ANC, is an exception. However, 15% of the lakes
in this Wilderness were below 100 µeq/l ANC and
can be considered sensitive. Phosphate data are
not presented because it was not detected in any of
the lakes. This reflects the detection limit of the
analysis rather than the presence or absence of
phosphate. Variable levels of phosphate were
likely present at low concentrations; phytoplank-
Figure 1. Statistical box plot of acid neutralizing capacity
in µeq/l (micro equilvalents per liter) for lakes
sampled in 1995. The solid rectangle is the range
of 50% of the values; the dot is the median value;
the dashed lines are the range of all observations; and the open circles are the outlier values.
ton population dynamics can respond to phosphate levels below the detection level of some
analytical techniques.
There were detectable1 levels of nitrate in many
of the lakes (figure 2), suggesting that they could
1
Some of the data presented in table 1 are below the
determined detection limits. The reader should be aware of the
uncertainty of those data. Detection limits were calculated
following Environmental Protection Agency methods as “three
times the standard deviation of 10 nonconsecutive reagent or
calibration blank analyses” (EPA 1987).
Figure 2. Nitrate concentration in wilderness lakes by sampling date.
11
be nitrogen saturated. Further experimentation is
necessary to verify saturation. The data also show
that samples collected early in the season had
nitrate concentrations higher (figures 2 and 3) than
those collected later in the season. The earlier
samples were probably influenced by the late
snowpack runoff. Nitrates were frequently higher
in lake inlet streams to than outlet streams (figure 4). This may be a reflection of the shorter
residence time in streams versus lakes and the
decreased opportunity for exchange in streams
with soil and biota compared to lakes.
Chemical composition will be correlated with
catchment physical characteristics in future manuscripts. Landscape habitat and soil type were
identified from topographic and soils maps and
were field verified. The data will be stratified and
analyzed by latitude/longitude, elevation, geology, soil type, terrain features, and landscape
characteristics to determine if these factors influence nitrogen saturation. Sites with particularly
low ANC and particularly high nitrate levels will
be resampled for water chemistry at more frequent
intervals, and sampled for phytoplankton species
and biomass to verify timing, extent, and source of
any possible saturation. Further analyses will be
Figure 4. Box plot of nitrate concentration in µeq/l (micro
equilvalents per liter) for lakes sampled in
1995 comparing difference between lake
inlets and outlets (inlet minus outlet). The
solid rectangle is the range of 50% of the
values; the dot is the median value; and the
dashed lines are the range of all observations.
conducted to compare stream versus lake data for
nitrate content. Phosphorus concentrations also
will be closely monitored.
Changes in nitrogen input to wilderness ecosystems can affect the nutrient balance and species
assemblages of these systems. High-elevation
mountainous aquatic ecosystems in the Front
Range are particularly sensitive to these changes.
Understanding the susceptibility and response of
aquatic ecosystems to the direct input of atmospheric deposition is important for wilderness
managers maintaining ecosystems for future use.
The data from this study provide information on
the impact of pollutants from point sources that
are located near wilderness areas.
LITERATURE CITED
Aber, J.D.; Nadelhoffer, K.J.; Steudler, P.; Melillo,
J.M. 1989. Nitrogen saturation in northern forest
ecosystems. BioScience 39: 378-386.
Arno, S.F.; Hammerly, R.P. 1984. Timberline.
Mountain and Arctic Forest Frontiers. The
Mountaineers. Seattle. 304 pg.
Baron, J.S.; Ojima, D.S.; Holland, E.A.; Parton, W.J.
1994. Analysis of nitrogen saturation potential in
Rocky Mountain tundra and forest: implications
for aquatic systems. Biogeochemistry 27: 61-82.
Figure 3. Box plot of nitrate concentration in µeq/l (micro
equilvalents per liter) for lakes sampled in
1995 comparing the difference between early
and late sampling dates (early minus late).
The solid rectangle is the range of 50% of the
values; the dot is the median value; and the
dashed lines are the range of all observations.
12
Bowman, W.D. 1992. Inputs and storage of nitrogen in winter snowpack in an alpine ecosystem.
Arctic and Alpine Research 24: 211-215.
Campbell, D.H.; Clow, D.W.; Ingersoll, G.P.; Mast,
M.A.; Spahr, N.E.; Turk, J.T. 1995. Processes
controlling the chemistry of two snowmeltdominated streams in the Rocky Mountains.
Water Resources Research 31(11): 2811-2821.
Eilers, J.M.; Kanciruk, P.; McCord, R.A.; Overton,
W.S.; Hook, L.; Blick, D.J.; Brakke, D.F.; Kellar,
P.E.; DeHaan, M.S.; Silverstein, M.E.; Landers,
D.H. 1987. Western Lake Survey. Phase I.
Characteristics of Lakes in the Western United
States. Volume II. Data Compendium for Selected Physical and Chemical Variables. EPA/
600/3-86/054b. U.S. Environmental Protection
Agency, Washington, D.C.
Environmental Protection Agency. 1987. Handbook of methods for acid deposition studies.
Laboratory analyses for surface water chemistry. EPA 600/4-87/026. U.S. Environmental
Protection Agency, Washington, D.C.
Irving, P. (ed). 1991. Acidic Deposition: State of
Science and Technology. Summary Report of the
U.S. National Acid Precipitation Assessment
Program. Washington, D.C.
Kendall, C.; Campbell, D.H.; Burns, D.A.; Shanley,
J.B.; Silva, T.R.; Chang, C.C.Y. 1995. Tracing
sources of nitrate in snowmelt runoff using the
oxygen and nitrogen isotopic compositions of
nitrate. Biogeochemistery of Seasonally SnowCovered Catchments. Proceedings of a Boulder
Symposium, July 1995. pg 339-347. IAHS Publ.
No 228.
Landers, D.H.; Eilers, J.M.; Brakke, D.F.; Overton,
W.S.; Kellar, P.E.; Silverstein, M.E.; Schonbrod,
R.D.; Crowe, R.E.; Linthurst, R.A.; Omernick,
J.M.; Teague, S.A.; Meier, E.P. 1987. Western
Lake Survey. Phase I. Characteristics of Lakes in
the Western United States. Volume I. Population
Descriptions and Physioco-Chemical Variables.
EPA/600/3-86/054a. U.S. Environmental
Protection Agency, Washington, D.C.
Morris, D.P.; Lewis, W.M. Jr. 1988. Phytoplankton
nutrient limitation in Colorado mountain lakes.
Freshwater Biology 20: 315-327.
Musselman, R.C. (technical coordinator). 1994. The
Glacier Lakes Ecosystem Experiments Site.
Rocky Mountain Forest and Range Experiment
Station, RMS General Technical Report RM-249.
Fort Collins, Colorado.
Smith, W.H. 1992. Air pollution effects of forest
processes. Chapter 11 in Baker, J.R. and Tingey,
D.T. eds. Air Pollution Effects on Biodiversity.
Van Nostrand Reinhold, New York.
Weber, W.A. 1976. Rocky Mountain Flora. Colorado Associated University Press. 479 pg.
Williams, M.W.; Caine, N.; Baron, J.; Sommerfeld,
R. 1993. Is nitrogen saturation occurring in the
Colorado Front Range Abstracts. LTER All
Scientists Meeting and International Summit.
September 18-24, 1993. Estes Park, Colorado.
LTER Network Office, Seattle, Washington.
Williams, M.W.; Baron, J.S.; Caine, N.;
Sommerfeld, R.; Sanford, R. Jr. 1996. Nitrogen
saturation in the Rocky Mountains. Environmental Science & Technology 30: 640-646.
Williams, M.W. 1994. Institute of Arctic and
Alpine Research, University of Colorado. Unpublished Data.
13
ACKNOWLEDGMENTS
This study was initiated as a cooperative effort between the Arapaho and Roosevelt
National Forests and the Rocky Mountain Forest and Range Experiment Station. The
National Forest was interested in a synoptic study of high-elevation lake water
chemistry and the Research Station was interested in sensitivity of high-elevation lakes
to atmospheric deposition. The University of Colorado has been studying water
nitrogen saturation in Front Range aquatic ecosystems. A study plan was written and
approved by USDA Forest Service researchers. Sample analyses for most lakes were
funded by the respective National Forests or by Forest Service Research. The
University of Colorado funded their sample analyses. We gratefully acknowledge the
assistance of the volunteers who attended sample collection training and collected the
water and stream samples for this study. We acknowledge personnel in the Rocky
Mountain Forest and Range Experiment Station Water Analysis Laboratory who
filtered and analyzed the National Forest and Forest Service Research samples. We
thank Christi Gordon, Leslie Dobson, and Andrea Sears for use of data from their
National Forests in this report. We acknowledge Jill Baron, National Biological Service,
for assisting in one of the sample collection training sessions. We are particularly
grateful to students Tim Platt-Mills, University of Colorado at Boulder and Yale
University, who collected the University of Colorado samples, and Darrel Jury,
Colorado State University, who compiled the list of Arapaho and Roosevelt National
Forests Wilderness lakes to sample and assisted in sample collection and data
compilation. We thank Rudy King for advice and assistance with data analysis.
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should contact the USDA Office of Communications at (202) 720-2791.
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U.S. Department of Agriculture
Forest Service
Rocky Mountain Forest and
Range Experiment Station
Rocky
Mountains
The Rocky Mountain Station is one of eight regional
experiment stations, plus the Forest Products
Laboratory and the Washington Office Staff, that make
up the Forest Service research organization.
RESEARCH FOCUS
Research programs at the Rocky Mountain Station are
coordinated with area universities and with other
institutions. Many studies are conducted on a
cooperative basis to accelerate solutions to problems
involving range, water, wildlife and fish habitat, human
and community development, timber, recreation,
protection, and multiresource evaluation.
Southwest
RESEARCH LOCATIONS
Research Work Units of the Rocky Mountain Station
are operated in cooperation with universities in the
following cities:
Great
Plains
Albuquerque, New Mexico
Flagstaff, Arizona
Fort Collins, Colorado
Laramie, Wyoming
Lincoln, Nebraska
Rapid City, South Dakota
*Station Headquarters: 240 W. Prospect Rd., Fort Collins,CO 80526