Great Basin and Owyhee Uplands
61. Fort Rock Viewpoints
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Return to Regional Geographic ModelAerial views of Fort Rock.
Above:Wave cut benches on walls of Fort Rock, an extinct volcano. Note irrigated
fileds today.
Below: Aerial views of Fort Rock.
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Geomorphology
Fort Rock was formed when upward-moving lava in the earths's crust encountered
undergroound water with powerful landscape forming effects. Upon contact
with the cooler water, the hot lava exploded, creating a cirucular crater.
Rocks and ash were thrown in the air, settling close to the crater building
up a high rim, or tuff ring.
Climate
During the late Pleistocene, up to 11,000 years ago, large and small lakes
characterized the Great Basin in Oregon, Neveda, and Utah. During the highwater
periods of the wetter Pleistocene era, Silver Lake, Chistmas Lake, Fossil
Lake, and Fort Rock were interconnected, the contiguous broad lake reaching
a maximum depth of over 200 feet. Some of the higher elevations as Fort
Rock were actually islands. The unusual shape of Fort Rock, with the wide
breach in the south rim (see photos above) was due to wave action from a
fomer lake here eroding the thins walls of the ring. (See Regional Geographic
model for current climate.)
Vegetation
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Wildlife
Today the steep 200 feet walls of Fort Rock provide excellent habitat for
raptors. Look for golden eagle, red-trailed hawk, prairie falcon, rock dove
and raven. See the Oregon Wildlife Viewing Guide (1994) for
important additional details on wildlife description, viewing information,
and directions to wildlife viewing sites.
Human Settlement
In 1938, prehistoric artifacts were discovered by archeologists in a large
cave at the base of Reub Long Butte just northwest of Fort Rock. This cave
yeilded weapons, tools and even sagebrush sandals. The sandals were carbon
dated to be 9000 years old and are now in the collection of the Oregon Museum
of Natural History at the University of Oregon, Eugene. At one point in
the distanct past, Fort Rock was likely a home to indigenous people who
traveled back and forth by boat in the wetter climate of the past. Today,
the closest town is Fort Rock, a reminder of an active Euro-American homestead
past. Today Fort Rock, is an important producer of alfalfa with the help
of irrigation. (see photo above)
Sources
ExplOregon , CD-ROM, 1995. University of Oregon, Departments
of Geography and Fine and Applied Arts.
Orr, l., Orr, W., and Baldwin, E. 4th Ed., 1992. Geology of Oregon.
. Kendall/Hunt, Dubuque, Iowa.
Yuskavitch, J., Oregon Wildlife Viewing Guide , 1994. Falcon
Press, Helena, Montana.
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Copyright
Phil Kessinger, 1997
Eugene,Oregon USA
All Rights Reserved
phil_k
at
efn.org
Revised December 2002