Information Regarding the Origin and Genetic Characteristics of Westslope
Cutthroat Trout in Oregon and Central Washington
2/15/03
Philip Howell
USDA Forest Service
La Grande Forestry and Range Sciences Laboratory
1401 Gekeler
La Grande, OR 97850
541-962-6559
phowell@fs.fed.us
Paul Spruell
Wild Trout and Salmon Genetics Laboratory
Division of Biological Sciences
University of Montana
Missoula, MT 58812
Additional genetic analysis:
Robb Leary
Wild Trout and Salmon Genetics Laboratory
Division of Biological Sciences
University of Montana
Missoula, MT 58812
Introduction
In 1999 we began a study of the origin, genetic variation, and hybridization of
westslope cutthroat trout (Oncorhynchus clarki lewisi (WSCT) in the John Day
subbasin in Oregon and Columbia River tributaries along the east slope of the
Cascade Range in Washington, which occur as disjunct populations from the
core distribution of WSCT in Idaho, Montana, SE British Columbia, and SW
Alberta. Another distinguishing characteristic of these populations is that most
them, where they are native, would have evolved with native rainbow trout
(Oncorhynchus mykiss) (RB) as anadromous (steelhead), fluvial, or resident
forms. Proebstel et al. (1997) examined some westslope cutthroat and rainbow
populations in the Methow, Entiat, and Wenatchee basins using mtDNA and
morphological and meristic characteristics. However, sample sizes were
variable, a number of them small (5 or less), and streams were not systematically
sampled throughout the distribution. In some cases their analysis was limited to
morphological and meristic characteristics. They recommended further work to
explore differences between “local native” westslope cutthroat vs. more “typical”
westslope cutthroat they observed and analysis of genetic variation among
westslope cutthroat populations since their analysis was limited primarily to
identifying species/subspecies purity.
Our primary objectives are to 1. Compare genetic population structure of Oregon
and Washington populations with populations from the core distribution, 2.
Compare allele frequencies of Washington populations with the Twin Lakes
hatchery stock of WSCT that has been extensively stocked in central
Washington, 3. Determine the magnitude and distribution patterns of
hybridization, 4. Examine the cutthroat and rainbow trout stocking histories in the
watersheds sampled for possible influence on the origin and hybridization of the
populations. This work is in progress. We offer the following information and
preliminary results for your consideration in the status review being conducted.
Methods
We sampled 9 watersheds and 2 mainstem reaches in the John Day subbasin in
Oregon and 14 watersheds and mainstem reaches in Washington in the Yakima,
Wenatchee, Entiat, Lake Chelan, Methow, and Okanagon subbasins (appendix
1). We initially classified each watershed into allopatric WSCT, sympatric WSCTRB, and allopatric RB distribution zones based on available information. This
strategy is based on a general distribution pattern of allopatric westslope
cutthroat in upper reaches, sympatric cutthroat/rainbow trout in middle reaches,
and allopatric rainbow trout in lower reaches. These were later adjusted in the
field based on specific distribution patterns observed in the watershed. The
objective of this stratification was to systematically assess WSCTXRB
hybridization through the distribution of the two species and longitudinally
through the watershed. Thirty tissue samples for PINEs analysis of hybridization
(Spruell 2001) were randomly collected from 10 fish in three reaches in the
sympatric cutthroat/rainbow (S) and allopatric rainbow trout (R) distribution
zones. Ten fish (30 total) were randomly collected in each of three reaches in the
allopatric cutthroat zone (C) for allozyme analysis to compare with other samples
from Idaho, Montana, and the Twin Lakes hatchery stock, which had been
previously sampled by and the data provided by the Washington Department of
Fish and Wildlife.
Preliminary Findings and Discussion
Historical Distribution
The lack of historical documentation of the presence of WSCT in Oregon and
central Washington clouds definitive delineation of its historical range in these
areas. In the previous status review (USFWS 1999) the historical distribution in
central Washington (attributed to Behnke 1992) was described to include the
Methow River and Lake Chelan drainages in Washington and the John Day
drainage in Oregon. This same distribution is used by Shepard et al. (2003).
However, Behnke (1992) indicated that WSCT were probably also native to the
Wenatchee and Entiat drainages. Behnke (2002) recently included the Yakima
subbasin in the historical range.
Widespread releases of hatchery cutthroat trout since circa 1900, including
stocks of WSCT, primarily Twin Lakes and Chelan/Stehekin in central
Washington, add to the uncertainty. Unfortunately, stocking records for
Washington and Oregon have large gaps. In the Methow subbasin Foggy Dew,
Cedar, Early Winters, Eightmile, Eureka, Goat, Horseshoe, NF Wolf and
Robinson creeks and Lost and WF Methow rivers have been suggested as
possible native populations (WDFW 1998); however, all of these drainages have
also been stocked with WSCT, at least in the headwater lakes (WDFW 1998). In
Oregon (John Day subbasin) the only documented introductions of WSCT were
in the NF John Day drainage (Gunckel 2002). The area of these introductions
accounts for all of the areas currently occupied by WSCT in the NF John Day.
WSCT from Anaconda Hatchery in Montana were also cultured in Oregon
hatcheries (1921-38)(Gunckel 2002), but the release locations are unknown.
To evaluate the influence of hatchery introductions, we compared allozyme allele
frequencies of WSCT samples from Oregon and Washington to those of the Twin
Lakes hatchery stock. Six variant alleles were detected in the samples that were
not present in the Twin Lakes stock or in some cases in samples collected
elsewhere in Washington, Idaho, and Montana:
Allele
GPI-A*100
GPI-B2*145
LDH-A2*0
LDH-B2*76
sOD-1*40
Population
WF Teanaway (Yakima)
Buck (Wenatchee)
Goat (Methow)
Nile (Yakima)
Mad (Entiat)
Early Winter C1 (Methow)
Deardorff C1, Beech (John Day)
Stafford (Yakima)
Early Winters C2-3 (Methow)
Based on these data, it is highly unlikely that these populations were the result of
stocking from the Twin Lakes Hatchery, and it is compelling evidence that they
are representative of native westslope cutthroat populations in the Yakima,
Wenatchee, Entiat, Methow and John Day subbasins.
In the Methow subbasin, as mentioned, NF Wolf Cr. is suggested as a potential
native population with current potential to support WSCT (WDFW 1998).
However, in 2000 we collected no fish that phenotypically appeared to be WSCT
in 5 reaches sampled. Samples analyzed were a hybrid swarm (Appendix 1).
WSCT samples collected from upper Wolf Cr. contained the PGM-2*85 allele,
which is present in the Twin Lakes hatchery stock but does not occur in other
Washington or Oregon samples.
Genetic Variation and Population Structure
Genetic analysis based on allozyme electrophoresis was completed on 176
populations of westslope cutthroat trout from throughout their range in the US,
including Oregon and central Washington. The relationships among those
populations are complex (Appendix Fig. 1). Although most Oregon and
Washington samples form two clusters both containing a mix of OR-WA
populations that are exclusive of other eastern populations, there are also major
population differences among and within basins. For example, Wolf Cr. and
particulary Early Winters Cr., both in the Methow subbasin, are quite different
from each other, the other Methow population analyzed (Goat Cr.), and other
Oregon-Washington populations. The most likely explanation for this pattern is
random genetic drift in small, isolated populations. This explanation is also
supported by the observation that substantial differences in allele frequencies are
often observed even between geographically nearby samples (e.g., Stafford C1
vs. C2-3, Deardorff C1 vs. C2-3, Goat C5 vs C3-4, Early Winters C1 vs. C2-3).
Some of these distinctive sample groups were collected less than 1 km apart.
This distribution of genetic variation makes defining DPSs based on genetic data
difficult in that neighboring populations may be as genetically different from each
other as either is from a population in another basin. It is important to note that
the lack of concordance between genetic differentiation and geographic distance
does not suggest that all westslope populations are genetically homogeneous-exactly the opposite is true. In other words, we would not conclude that
Washington and Oregon samples are genetically similar to eastern populations.
Hybridization
Genetically “pure” WSCT were found principally in suspected allopatric WSCT
zones in the upper reaches of distribution of most of the populations analyzed.
However, the distribution of pure WSCT in these reaches can be limited to a few
km.
Pure WSCT populations analyzed:
John Day—Deardorff, Strawberry, Beech, Upper Mainstem
WA—Wildcat, SF Little Naches, WF Teanaway, Oak, Nile, Buck,
Fall, NF Entiat, Mad, Early Winters, Goat, Wolf
Hybridized allopatric WSCT zone:
John Day—Birch (hybrid swarm), MF Canyon (6% F1), Bear (see
Appendix 1)
WA—Negro (hybrid swarm), Snowy (88% pure WSCT, 12%
hybrids), Stafford (90% pure WSCT, 10% hybrids), Toats
(hybrid swarm)
There appear to be 2 general patterns downstream of allopatric WSCT zones in
the suspected sympatric WSCT-RB (S) and allopatric RB (R) zones:
1. Mix of parentals (pure WSCT and RB) and hybrids primarily in S
reaches, decreasing WSCT contribution and increasing RB
contribution moving downstream from S to R.
This pattern suggests recent hybridization, a degree of reproductive
isolation within the reach or parentals sampled were derived from
reproductively isolated groups.
There are two variations of this pattern:
A. Mix of parentals and hybrids transition to pure allopatric RB
John Day—Deardorff, Beech, Clear
WA—Nile, WF Teanaway, L. Naches
B. Mix of parentals and hybrids transition to a hybrid swarm
John Day—Upper main stem
WA--Stafford
2. Little transition from allopatric WSCT to a hybrid swarm
John Day—Fields, Strawberry
WA—Early Winters, Goat, Wolf, Snowy/Rainey, NF Entiat, Oak
Hybrid swarms extended from tributaries into the main stems of the John Day,
Entiat, and Methow rivers. High levels of hybridization occurred in suspected
allopatric RB reaches, where fish ostensibly appeared to be RB.
Populations that consisted of hybrid swarms throughout their distribution include
Birch, Negro, Toats, and likely Bear.
It is apparent that WSCT X RB hybridization can be extensive in areas, such as
the John Day subbasin, where both taxa are native and there have been little to
no introductions of hatchery RB.
Literature Cited
Behnke, R. J. 2002. Trout and salmon of North America. The Free Press. NY,NY.
Behnke, R. J. 1992. Native trout of Western North America. American Fisheries
Society, Monograph 6, Bethesda, Maryland.
Gunckel, S. 2002. Stocking history of westslope cutthroat trout and rainbow trout
in the upper John Day basin, Oregon. Unpublished report. Oregon
Department of Fish and Wildlife. Corvallis, Oregon
Proebstel, D.S., R.J. Behnke, and S.M. Noble. 1997. Draft Report. Identification
of salmonid fishes from tributary streams and lakes of the Mid-Columbia
basin. Department of Fishery and Wildlife Biology, Colorado State
University, Fort Collins, and U.S. Fish and Wildlife Service, Leavenworth,
Washington.
Shepard, B. B., B. E. May and W. Urie. 2003. Status of westslope cutthroat trout
(Oncorhynchus clarki lewisi)in the United States: 2002. Unpublished
report.
Spruell P, Bartron ML, Kanda N, Allendorf FW. 2001. Detection of hybrids
between bull trout (Salvelinus confluentus) and brook trout (Salvelinus
fontinalis) using PCR primers complementary to interspersed nuclear
elements. Copeia 2001:1093-1099.
U.S. Fish and Wildlife Service (USFWS). 1999. Status review for westslope
cutthroat trout in the United States. United States Department of Interior,
U.S. Fish and Wildlife Service, Regions 1 and 6, Portland, Oregon and
Denver, Colorado.
Washington Department of Fish and Wildlife (WDFW). 1998. Unpublished status
review of westslope cutthroat trout in Washington. Olympia, Washington.
Appendix 1.
Streams Sampled
Basin
Stream
John Day
Deardorff
Strawberry
Beech
Birch
Bear
MF Canyon
C
1-3
1-3
1-4
1-3
1-3
1-3
Canyon
Reach No.
S
R
1-3
1-3
1-3
1a,1-4
1-3
1-3
1-3
1-2
1-3
1-2
3-5
3-5
1-3
1-3
Fields
Upper main stem (above
Reynolds Cr.)
(John Day-Reynolds Cr.)
Lower main stem (below John
Day)
Clear/Granite (NFJD)
1-3
1-3
0-3
1-3
1-4
Yakima
Wildcat
SF L Naches
WF Teanaway
Staf/NF Tean
Oak
Nile
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1-3
1
1-4
1-2
1-4
1-3
Wenatchee
Negro/Peshastin
Buck
Snowy/Rainy
1-4
1-3
1-3
1-3
Chelan
Fall
1-3
Entiat
NF
Main stem
Mad
1-3
3
1-3
1-3
1-3
1-3
4-5
1-3
Wolf
1-3
1-3
Toats
1
1-3
Methow
Early Winters
1-3
1-3
1-3
1-3
Methow R.
Goat
1
Methow R.
Okanagon
2-3
1-3
1-3
1
1-2
Preliminary Hybridization Results
John Day
Fields Cr.
Reach
S1
S2
S3
RB%
10
70
20
R1
R2
R3
10
40
70
WSCT% HYBRID%
0
90
0
20
0
80
0
0
0
90
60
30
S1-3,R1-3: Hybrid swarm predominantly RB alleles
Birch Cr.
C1-3: Hybrid swarm (97% WSCT, 3% RB), 1 RB
S1-3, R 1-2: hybrid swarm with predominantly RBT alleles and a low level
admixture from WSCT
Beech Cr.
C1-3: WSCT
S 1-3: Mix of RB, WSCT, F1
R1 all appear to be RBT
R2 predominantly RBT hyb swarm with low level admixture from WSCT
R3 predominantly RBT hyb swarm with low level admixture from WSCT
MF Canyon/Canyon Cr.
RBT% WSCT%
MF Canyon
C1
91
C2
90
C3
100
S3
10
60
S4
20
60
S5
40
30
Canyon Creek
S4
80
0
S5
70
20
S6
40
20
H%
9
10
0
20
30
20
10
30
MF Canyon
C1-2: 1 F1 hybrid in each
C3: WSCT
S3: 8 WSCT, 1 RBT and one recent hybrid
S4: Both parentals appear to be present but 2/10 indivdiuals are hybrids
post F1
S5: Both parentals appear to be present but 3/10 indivdiuals are hybrids
post F1
Canyon
S4: 8 RB, 2 hybrids,a single WSCT allele detected
S5: 7 RB, 2 WSCT, 1 hybrid
S6: Both parentals present and 3 hybrids post F1
Bear Cr.
S1:
S2:
S3:
R1:
R2:
95% RBT 5% WSCT hybrid swarm
96% RBT 4% WSCT hybrid swarm
only RBT alleles detected
only RBT alleles detected
a single WSCT allele detected
C1-3: Allozyme analysis is not completed; however, 8 of 23 samples in C2-3
were phenotypically identified as hybrids, and 1 was phenotypically identified as
a RBT
Strawberry Cr.
C1-3: WSCT
S3: hybrid swarm with predominantly alleles WSCT and a low level admixture
from RBT
S 1-2, R1a,1-3: hybrid swarm with predominantly RBT alleles and a low level
admixture from WSCT
Deardorff Cr.
C 1-3: WSCT
S2: 4 WSCT, 6RBT, 1 F1
S3: 6 WSCT, 1 RBT, 3 F1
R1: all rainbow trout
R2: mix of hybrids, both parentals, recent hybridization
R3: mixture of parentals, 4 WSCT, 3 RBT
Upper main stem John Day R.
C1-3: WSCT
S1: includes both parental types and recent hybrids. Either hybridization is a
recent event or these samples represent individuals collected from
several reproductively isolated groups.
S2: 5 apparent RBT, 4 apparent WSCT, 1 F1
S3: hybrid swarm, F1’s and beyond
R1: 91% RBT 9% WSCT hybrid swarm
R2: 94% RBT 6% WSCT hybrid swarm
R3: 93% RBT 7% WSCT hybrid swarm
Lower main stem John Day R.
R1: 92% RBT 8% WSCT hybrid swarm
R2: 95% RBT 5% WSCT hybrid swarm
R3: 92% RBT 8% WSCT hybrid swarm
Clear Cr.
C2-3: 4 suspected H confirmed in C2, 1 in C3, predominantly WSCT but
substantial admixture of RB
Clear Creek
Reach
S0
S1
S2
S3
RB% WSCT% HYBRID%
40
10
50
0
40
60
20
70
10
10
60
30
S0-3: both parentals and a mixture of both recent and post F1 hybrids
R1-4: predominantly RBT but substantial admixture with WSCT
Methow
Early Winters Cr.
C1-3: WSCT
S3: hybrid swarm with predominantly RBT alleles and a low level admixture from
WSCT
S1: 78% RBT 22% WSCT hybrid swarm
S2: 65% RBT 35% WSCT hybrid swarm
R1 (main stem Methow R. below Early Winters Cr.): 80% RBT 20% WSCT
hybrid swarm
Goat Cr.
C1-3: WSCT
S1: 96% RBT 4% WSCT hybrid swarm
S2: 95% RBT 5% WSCT hybrid swarm
S3: 51% RBT 49% WSCT hybrid swarm
R1 (main stem Methow R. upstream of Wolf Cr.): 89% RBT 11% WSCT hybrid
swarm
Wolf Cr.
C1-2: WSCT
S1: only WSCT alleles detected
S3: 89% RBT 11% WSCT hybrid swarm
S2 (NF Wolf. Cr.): 89% RBT 11% WSCT hybrid swarm
(Note: No phenotypic WSCT were found during sampling of 4 reaches up to
approx. RK 4)
Wenatchee
Snowy/Rainey
C1: 3 suspected hybrids confirmed--predominantly WSCT but all carry at least
one RBT allele
C1-3: Allozyme sample (N=30): 29 WSCT, 1 H F1
S2: WSCT
S3: WSCT
S1: Hybrid swarm, almost all individuals carry 2 or more alleles from each
species
Negro Cr.
C1-2: Hybrid swarm (97% WSCT, 3% RB)
S1: 93% RBT 7% WSCT hybrid swarm
S2: 89% RBT 11% WSCT hybrid swarm
S3: 94% RBT 5% WSCT hybrid swarm
R1-2: hybrid swarm
Buck Cr.
C1-3: WSCT
Entiat
NF Entiat R.
C1-3: WSCT
S3, R2-3: Hybrid swarm
Main stem Entiat R.
R1: 96% RBT 4% WSCT hybrid swarm
R2: 93% RBT 7% WSCT hybrid swarm
R3: 98% RBT 2% WSCT hybrid swarm
Mad River
C1-3: WSCT
S1-2: hybrid swarms with predominantly WSCT alleles and a low level admixture
from RBT
R1: 97% RBT 3% WSCT hybrid swarm
R2: 96% RBT 4% WSCT hybrid swarm
R3: 94% RBT 6% WSCT hybrid swarm
Lake Chelan
Fall Cr
C1-3: WSCT
Yakima
Oak Cr.
C1-3:WSCT
Reach
S1
S2
RB% WSCT% HYBRID%
20
50
0
0
80
50
S3
10
40
50
R1
R2
R3
R4
30
30
40
40
0
0
0
0
70
70
60
60
S1: Hybrid swarm (85% RB, 15% WSCT)
S2-3: one F1 and several individuals hybridized to various extent in each reach
R1-4: Hybrid swarm with low level WSCT introgression
Nile Cr.
C1-3:WSCT
Reach
S1
S2
S3
RB%
50
20
10
WSCT%
10
10
50
HYBRID%
40
70
40
R1
R2
R3
90
80
100
0
0
0
10
20
0
S1: Both parentals appear to be present but 4/10 indivdiuals are recent hybrids
S2: Both parentals appear to be present but 7/10 indivdiuals are recent hybrids
S3: a few pure WSCT remain but 6/10 individuals are hybrids
R1: 1 WSCT allele
R2: low level WSCT introgression
R3: RB
Little Naches
S1: mostly WSCT, low level admixture with RBT
S2: mostly RBT, one allele may indicate low level admixture
S3: mostly WSCT, low level admixture with RBT, 2 recent (but not F1, hybrids)
R1: mostly RBT, one allele may indicate low level admixture
WF Teanaway
S1: predominantly RBT hyb swarm with low level admixture from WSCT
S2: predominantly WSCT with low level admixture from RBT
S3: mixture of putative parentals and recent hybrids
R1: 1 WSCT, 2 RBT
R2: mostly RBT, one locus suggests admixture w/ WSCT
R3: mostly RBT, one locus suggestis admixture w/ WSCT
R4: 3 RBT, one hyb
Stafford/NF Teanaway
C1: 1 suspected hybrid confirmed
C1-3 allozyme sample: 28 WSCT, 1 F1, 1 beyond F1
S1: hybrid swarm with predominantly RBT alleles and a low level admixture from
WSCT
S2: 5 WSCT, 1 apparent RBT, 2 F1, 2 beyond F1
S3: 5 WSCT, 3 hybrids with 1 RBT allele, 2 hybrids with higher proportion of RBT
alleles
R1-2: hybrid swarm
Okanogan
Toats
R1-2,S1-3, C1: hybrid swarm with predominantly RBT alleles and a low level
admixture from WSCT
SFH02
LFH01
CLW01
CLW02
YMA04
YMA07
JDY01
YMA01
YMA06
YMA02
YMA03
MET04
JDY04
JDY03
JDY05
MMS01
DEP01
RBY01
SFH01
SAL02
YMA05
CLN01
JDY02
WEN01
ENT01
MET03
WEN02
TMD02
NFH04
BL
07
T
MMS05
BGH01
ST
02
L
LCF07
YAK01
SFH08
LCF01
UCF07
ENT02
SSK01
LK
08
T
LK
10
T
NFH07
UKT08
SAL03
SFH07
MMS03
LCF09
NFH01
STH01
GLN01
BL
05
T
BL
04
T
BL
01
T
JUD01
MSL01
TMD03
TMD01
BXE01
TTN03
MMS02
BVR02
BVR01
YAK02
LK
09
T
LK
07
T
LK
06
T
LK
01
T
SWN02
SWN01
LFH09
LFH06
NFH08
NFH06
NFH05
SFH09
UCF04
UCF02
SAL05
SAL07
NFH03
NFH10
STH03
STH02
TTN01
SFH10
SFH03
YAK03
BL
02
T
JF
03
MMS04
UCF01
BTR03
BTR06
LB
01
F
BL
06
T
UCF06
SAL06
BTR04
LFH04
SAL04
LFH10
MFH02
LFH07
YAK10
MFH03
ST
01
L
UKT07
UKT09
UKT04
MFH01
LFH02
NFH09
YAK04
SFH04
NFH02
SFH05
SFH06
YAK06
LB
03
F
CDA07
BLD01
LCF08
BTR08
LCF06
LCF05
LK
04
T
BTR09
BTR10
UCF05
UCF10
TTN04
TTN02
BL
03
T
LFH03
LFH05
LB
02
F
UCF03
UCF09
LCF02
UCF08
UKT01
UKT02
UKT10
BTR01
LCF03
BTR02
BTR05
BTR07
ST
01
J
MET05
MET06
LFH08
LK
05
T
CDA01
CDA02
CDA03
LK
02
T
YAK07
JF
02
CDA05
LK
03
T
CDA04
CDA06
BVR03
JF
01
SAL01
LCF04
MET01
MET02
UKT05
LCF10
UKT03
UKT06
0.01
Appendix Figure 1. UPGMA dendrogram of 176 westslope cutthroat trout samples based on
Cavalli-Sforza and Edward's chord distance and 25 polymorphic allozyme loci. Oregon
samples are highlighted in blue, Washington samples in red. Sample identifiers correspond to
site descriptions in Appendix Table 1.
YAK05
YAK09
Appendix Table 1. Sample codes used in appendix figure 1.
John Day
Deardorf C1
Deardorf C2 & C3
Strawberry
Beech
Main
Yakima
Wildcat
SF Little Natches
WF Teanaway
Stafford C1
Stafford C2 & C3
Oak
Wenatchee
Nile
Buck
Chelan
Snowy
Fall
Entiat
Methow
NF Entiat
Mad
Wolf C1
Wolf C2
Deep Creek
St. Joe
Deep
St. Joe
Clearwater
Brushy Fork
WF Mallard
Coeur d' Alene
Honey
Little NF CdA
Tom Lavin
Iron
Hudlow
Canyon Fork
Blackfoot
Lost Fork
MF Salmon
Pierson
Copper
Belmont
Humbug
Hogum
Sandbar
Little Blackfoot
JDY03
JDY04
JDY05
YMA01
YMA02
YMA03
YMA04
YMA05
YMA06
YMA07
WEN01
WEN02
CLN01
ENT01
ENT02
MET01
Early Winters C1
Early Winters C2 & C3 MET02
MET03
Goat C3 & C4
Goat C5
Salmon
JDY01
JDY02
Little Blackfoot
Ophir
Snowshoe
Lower Clark Fork Marten
MET04
MET05
MET06
DEP01
STJ01
CLW01
CLW02
CDA01
CDA02
CDA03
CDA04
CDA05
CDA06
CDA07
SAL01
SAL02
SAL03
SAL04
SAL05
SAL06
SAL07
LBF01
LBF02
LBF03
LCF01
Vermillion
O'Keefe
SF Little Joe
EF Trout
Prospect
Little Beaver
Deep
Grant
Oregon
upper Clark Fork Bateman
Cowan
Gimlet
Warm Springs
North Gold
Deer
Telegraph
Warm Springs
Douglas
Wood
Bitterroot
Granite
Sleeping Child
Meadow
Chaffin
Coal
Fred Burr
Skalkaho
Piquett
Burnt Fork
Little Blue Joint
MF Flathead
Challenge
Cox
Stillwater
MF Flathead
Fitzsimmons
SF Flathead
Chepat
White River
Marshall
Hungry Horse
Tin
Danaher
Gordon
Harris
Spotted Bear
Kneiff
NF Flathead
Lost Johnny
Nicola
Yackinikak
Coal
Cyclone
LCF02
LCF03
LCF04
LCF05
LCF06
LCF07
LCF08
LCF09
LCF10
UCF01
UCF02
UCF03
UCF04
UCF05
UCF06
UCF07
UCF08
UCF09
UCF10
BTR01
BTR02
BTR03
BTR04
BTR05
BTR06
BTR07
BTR08
BTR09
BTR10
MFH01
MFH02
MFH03
STL01
STL02
SFH01
SFH02
SFH03
SFH04
SFH05
SFH06
SFH07
SFH08
SFH09
SFH10
NFH01
NFH02
NFH03
NFH04
Depuy
Hay
Moran
McGinnis
Red Meadow
Lower Flathead
SF Coal
Cottonwood
Centipede
Jock S
Agency
Big Knife
Hewolf
NF Valley
Frog
Mill
Swan
Schley
Groom
Lower Kootenai
Soup
Ruby
American
Cannuck
Keno
Ross
Silver Bow
Fawn
Silver Butte
Good
upper Kootenai
Big Cherry
Dodge
Gold
Van
Aldrige
Skelly
Kutlis
Office
Skookumchuck
Wigwam
Yaak
Graves
upper Burnt
Wampoo
Seventeenmile
Fourth of July
Red Top
SF Meadow
Pheasant
French
WF Yaak, Can
Garver
NFH05
NFH06
NFH07
NFH08
NFH09
NFH10
LFH01
LFH02
LFH03
LFH04
LFH05
LFH06
LFH07
LFH08
LFH09
LFH10
SWN01
SWN02
LKT01
LKT02
LKT03
LKT04
LKT05
LKT06
LKT07
LKT08
LKT09
LKT10
UKT01
UKT02
UKT03
UKT04
UKT05
UKT06
UKT07
UKT08
UKT09
UKT10
YAK01
YAK02
YAK03
YAK04
YAK05
YAK06
YAK07
YAK08
YAK09
YAK10
Beaverhead
Brays Canyon
Buffalo
MF Stone
Jefferson
mid Missouri
Halfway (A)
Halfway (B)
Fish
Elkhorn
Whites Gulch
Three Mile
Prickly Pear
McCellan
Smith
Teton
NF Deep
Cottonwood
Fourmile
Cow
Waldron
NF Waldron
Big Hole
NF Willow
Lambrecht
Box Elder
Ruby
Collar Gulch
Geyser
Two Medicine
Lee
MF Dupuyer
Boulder
Dupuyer
Little Boulder
Musselshell
Judith
Halfmoon
EF Big Springs
Belt
Graveyard
Tillinghast
Gold Run
upper O'Brien
Pilgrim
Chamberlain
Gallatin
Harley
WF Wilson
S. Saskat
Wild
BVR01
BVR02
BVR03
JFF01
JFF02
JFF03
MMS01
MMS02
MMS03
MMS04
MMS05
STH01
STH02
STH03
TTN01
TTN02
TTN03
TTN04
BGH01
BXE01
RBY01
TMD01
TMD02
TMD03
BLD01
MSL01
JUD01
BLT01
BLT02
BLT03
BLT04
BLT05
BLT06
BLT07
GLN01
SSK01