Mammoth Changes
This landscape is arid today, but during the twilight of the last Ice Age, rain and runoff from
melting snow filled the surrounding lowlands creating large, freshwater lakes surrounded by lush
vegetation. To the south, Lake Chewaucan once covered 461 square miles at depths up to 375 feet.
Alkali Lake occupied the valley to the north, leaving this site high and dry. These lakes dried up,
concentrating salts and alkali into ever shrinking sings around 12,000 years ago. Today, Lake Abert
and Summer Lake are the only remnants of ancient Lake Chewaucan.
A giant beaver, 7 1/2 feet long, lived in Oregon during the Pleistocene.
{Elizabeth and William Orr, Ewart M. Baldwin, Geology of Oregon, 1992.
Reprinted by permission of Kendall/Hunt Publishing Company)
A long-limbed camel, 8-10 feet tall, once lived in eastern Oregon.
{Elizabeth and William Orr, Ewart M. Baldwin, Geology of Oregon, 1992.
Reprinted by permission of Kendall/Hunt Publishing Company)
Twelve thousand years ago, large herds of Ice Age bixon,
camels, horses and mammoths grazed the adjacent countryside,
while the vast marshes and open waters teamed with
waterfowl and fish. This land provided bountifully for its first
residents. Sagebrush sandals, tools, and weaphons have been
discovered in local caves, and the region presents many fine
examples of prehistoric rock art called petroglyphs.
Petroglyphs and other artifacts are sacred to Native Americans and they are
important for scientific study. These items are also protected by state and federal
laws. Please do not distrub antiquities, and report any vandalism to the Bureau of
Land Management in Lakeview or 1-800-333-7283.
