An easy stroll explores the inside of this fortress-shaped outcropping in the arid bed of a vanished Ice Age lake. A rougher route loops around the outside of ring’s cliff. Near here, in a cave overlooking what is now the sagebrush country of arid Fort Rock Valley, archeologists in 1938 unearthed a 9000-year-old cache of more than 70 sandals woven from sagebrush bark.

Originally, Fort Rock did not have cliff edges at all, but rather the gently sloping sides of a maar—a volcanic explosion crater. When Ice Age rainstorms filled the valley with a vast, 250-foot-deep lake 13,000 years ago, Fort Rock became an island, battered by storm waves from the south winds. The surf wore the outer slopes back to steep cliffs and then breached the crater’s south wall.

Amidst Fort Rock’s sagebrush you’ll find brilliant red paintbrush in June, yellow clumps of sunflower-like Oregon sunshine in summer, and yellow-tipped rabbit brush in fall. Cliff swallows swoop from mud nests high on the guano-stained rock walls, watched by prairie falcons. Avoid the heat of July and August. Winter months are windy and very cold.

From Bend, drive . . .

This chapter is an excerpt from 100 Hikes: Eastern Oregon