Table of Contents: **INSERT IMAGE: Sheep Rock & John Day River
DIGGING ANCIENT DIRT: THE JOHN DAY FOSSIL BEDS
Story by Vicki Andersen
From the soaring peaks of the snow-clad Cascade mountains and their adjacent year-round
playgrounds (see April-May 2008 for “Creation of the Cascade Mountains”), our geological
exploration of the Northwest leads us in the other direction: digging in the dirt.
While some rockhounds seek out samples laced with shimmering minerals, elusive gemstones
or concealed treasures like thundereggs, another group of excavators use small hammers and
trowels to pursue tangible evidence of life before man trod the earth. These are the fossil
hunters, and one of the richest research grounds beckons from Central Oregon.
**INSERT IMAGE: Fossil-Rich Blue Basin (Photo: USGS)
**INSERT IMAGE:
Columnar Basalt Pillars of the Clarno Palisades (Photo: USGS)
In the early 1860s, about the time Charles Darwin was turning scientific and pious worlds
upside down with his theory of evolution, an Oregon clergyman and pioneer geologist
encountered fossilized teeth and bones gathered in Central Oregon by a cavalry troop.
Thomas Condon realized this was important evidence supporting Darwin’s premise, and in
1865 he began searching the John Day Valley for more samples, eventually uncovering a
wealth of paleontology specimens. His numerous investigations lead to his 1872 appointment
as Oregon’s first state geologist.
Situated within the deeply eroded layers of volcanic ash that makes up what is called the John
Day Formation is a well-preserved history of the flora and fauna that flourished during 40
million years of the Cenozoic Era, known as the “Age of Mammals and Flowering Plants”.
Described as the world’s richest fossil beds from this Era, it is one of the Earth’s most
complete records of prehistoric life.
More than 100 different species of mammals have been uncovered, including some of the
earliest rhino fossils in the world. The John Day Fossil Beds have yielded at least 14 different
species of horses, who first evolved in North America 50 million years ago.
These fossils show that jungles, savannas and woodlands once prospered in this present-day
region of scenic badlands known as the John Day River Basin. Over 14,000 acres were
designated the John Day Fossil Beds National Monument in 1975, comprised of three
separate units encompassing more than 700 fossil sites, and continuing field investigations are
still uncovering new finds.
**INSERT IMAGE: Cathedral Rock & its Band of Volcanic Tuff (Photo: NWIA)
**INSERT IMAGE: Bridge Along the Blue Basin Trail (Photo: USGS)
SHEEP ROCK UNIT
Situated six miles west of Dayville, at the intersection of State Routes 26 and 19, stunning
geological formations in the Sheep Rock Unit include Cathedral Rock which broke off the John
Day Formation, slipped down a lofty precipice and caused the John Day River to reroute itself
into a horseshoe bend around the base of the massive Rock.
The blue-green volcanic ash of Blue Basin, a huge natural amphitheater sculpted out of the
John Day Formation, has turned to claystone. As this badlands-type outcropping continues to
erode, it yields a large variety of the most valuable fossils found in the John Day region.
The gently inclined half-mile Island in Time Trail terminates above Blue Basin, and features
interpretive signs and fossil replicas. The more strenuous 3-mile Blue Basin Overlook Trail
climbs six hundred feet to the rim of its namesake, offering spectacular views of the John Day
River Valley.
The Story in Stone Trail, an easy quarter-mile asphalt-surfaced path with short sections of
moderate incline, includes touchable exhibits of 25-30 million year-old animal fossils
embedded in the hillside. A self-guided brochure and audio-tape tour (including cassette
player) are available at the Visitor Center.
**INSERT IMAGE: Sheep Rock (Photo: USGS)
(Photo: NWIA)
**INSERT IMAGE: Picture Gorge
Sheep Rock, towering 1,100 feet above the John Day River, was monikered for the wild
bighorn sheep which thrived here, as well as a later sheep ranch. The diagonal brown layer is
a massive bed of volcanic ash known as a “tuff”. Its colorful layers reveal fossils from a time
when this region was covered by deciduous forests, approximately 25-28 million years ago,
when it was home to three-toed horses, rhinos, oreodonts, sabertoothed cat-like animals, and
lemur-like primates.
When the John Day River eroded a nearly 1,000-foot-long section out of the lava flow sixteen
million years ago, it created Picture Gorge. Native Americans eventually turned this into an art
gallery, decorating the walls with pictographs of people, animals and geometric designs.
The Thomas Condon Paleontology Center features exhibits, interpretive programs, and
audiovisual presentations about fossils, geology and paleontology. A window peers into the
laboratory where specimens from this region of still-active research are prepared for scientific
study.
**INSERT IMAGE: Paleontology Museum Display of Lion & Sabertooth Cats & Rhino
Skulls (Photo: USGS)
**INSERT IMAGE: Blue Basin (Photo: USGS)
The Cant Ranch Historical Museum, located a quarter-mile away, serves as the Monument
headquarters and Visitor Center. Indoor and outdoor exhibits relate the history of human
settlement on the ranch and in the region. Wheelchair accessible, you’ll find a bookstore,
restrooms, drinking fountains and shaded picnic area. The Visitor Center is open daily from
9:00 a.m. to 5:00 p.m. (6:00 p.m. Memorial Day to Labor Day) March through October, closed
weekends and holidays Thanksgiving through February.
**INSERT IMAGE: Interpretive Panel at the Palisades (Photo: NWIA)
IMAGE: Clarno Palisades (Photo: Vicki Andersen)
**INSERT
CLARNO UNIT
Eighteen miles west of Fossil on State Route 218 are the bluffs of volcanic tuff and basalt flows
known as the Clarno Unit. More than 300 species of plants have been identified in this area,
and unusual primeval finds in the Hancock Mammal Quarry are still being investigated. Trails
wind along lahars (volcanic mudflows) with embedded plant remains, through a subtropical
forest that perished over 45 million years ago, passing near petrified logs and alongside 40
million year old fossils.
The Clarno Nut Beds were created when the surrounding tropical forest (including banana
palms!) was overwhelmed by a massive lahar. Over time the wood, leaves, nuts and seeds of
the forest bonded together to form deep, rich layers of fossilized flora, fish and other fauna.
Restrooms, drinking fountains and picnic areas are available in this Unit.
**INSERT IMAGE: Palisades Revealed by an Eroding Stream (Photo: USGS)
**INSERT IMAGE: Large Diversity of Fossils were Preserved in the Palisades (Photo:
Vicki Andersen)
The most prominent landform of the Clarno Unit is the Palisades, whose cliffs are an
extraordinary example of columnar basalt pillars. This type of landscape forms when extra-hot,
very fluid lava covers a large area. Cooling fairly evenly, the lava shrinks and cracks, usually
forming the most efficient geometric pattern: hexagonal pillars. Two trails make their way from
the bottom of the Palisades for close-up surveillance of embedded remnants in the basalt.
This area is a treasure trove of fossils of tiny four-toed horses, huge rhino-like brontotheres,
crocodilians, and meat-eating creodonts who roamed the ancient jungles.
**INSERT IMAGE: Colorful Pallet of the Painted Hills (Photo: NWIA)
IMAGE: A Cuesta Crowns Carroll Rim (Photo: USGS)
**INSERT
PAINTED HILLS UNIT
The Painted Hills Unit is unsurpassed for geological splendor. Nine miles northwest of Mitchell
off State Route 26, you will find hummocks and hillsides of heavily eroded volcanic ash layers
bejeweled like an artist’s palette. The weathering of ash and passage of diverse climatic
periods has eroded and sculpted this section of the lower John Day Formation into dramatic
panoramas of yellows and golds, tans and blacks, and pinks and reds.
Leaf Hill Trail, an easy quarter-mile path, passes through remnants of a 30 million year-old
hardwood forest with fossilized leaf exhibits. Fossilized flora are typical of broad-leaf deciduous
trees that grew on the edge of streams and lakes.
The similar-length Painted Cove Trail circles a crimson-tinted hill for close-up inspection of the
popcorn-textured claystone; trail guides can be found at the trailhead The Painted Hills Unit
also offers exhibits, restrooms, drinking fountains and shaded picnic tables.
**INSERT IMAGE: Painted Hills Overlook View of Carroll Rim (Photo: USGS)
Carroll Rim, capped by a massive volcanic tuff deposit called a “cuesta”, was a source of many
fossils during the early exploration of this region. The moderately strenuous three-quarter-mile
Carroll Rim Trail climbs to the top of this 500-foot tall prominence for a dazzling view of the
Painted Hills and nearby Sutton Mountain. The rock forming the cliffs along the trail is a layer
of welded volcanic ash known as ignimbrite.
**INSERT IMAGE: John Day Fossil Beds National Monument (Photo: Vicki Andersen)
In the town of Fossil, behind the Wheeler County High School baseball field backstop, is a
fossil bed rich in flora and chances of taking something home is good to excellent. Your daily
collection limit is what you can hand-carry from the site in one trip to your vehicle, or about 25
pounds of rock.
Approximately 33 million years ago the Cascade Range spewed forth burst after burst of
volcanic ash which, along with organic material, washed into a lake basin. As these layers built
up and gradually hardened into stone, much of the flora left well-defined impressions of leaves,
fruit, cones, seeds and, infrequently, flowers. Nearly three dozen plant species such as alder,
beech, dawn redwood, maple and pine have been identified, as well as animal fossils including
an unidentified bat, a new species of salamander, frogs and numerous insects.
**INSERT IMAGE: Blue Basin (Photo: Vicki USGS)
Rock & John Day River (Photo: USGS)
**INSERT IMAGE: Cathedral
A site with a leaner but still potential chance to find fossils is near Mt. Vernon. On State Route
26 near milepost 144 is the intersection of Fields Creek Road. A couple hundred yards south
on Fields Creek Road is an Oregon Department of Transportation geologic marker identifying
a chalky embankment across the road. This formation is diatomaceous rock, consisting of the
calcium remains from millions of minuscule aquatic animals called diatoms. Within these 12-15
million year-old diatomic remnants can be found fossilized deciduous leaves and snails -- in
effect, fossils within fossils.
While collecting, digging or disturbing fossils or other geologic or biological resources is
prohibited within the Monument, visitors are welcome to try their luck at the Fossil and Mt.
Vernon sites.
Within the Monument, all drive-to overlooks have hard-packed surfaces. Park trails, overlooks
and grounds are open during daylight hours. Trails and picnic facilities are open all year, and
water is available at all picnic areas during the summer season. For brochures, maps or more
information contact the John Day Fossil Beds National Monument, Kimberly, OR at 541-9872333 or visit www.nps.gov/joda.