Coulee Rim Trail

Coulee Rim Trail follows the edge of the Grand Coulee above Banks Lake, delivering sustained views into one of North America's most impressive ice age landscapes while traversing the open sage-steppe ecosystem of the Columbia Plateau. The Grand Coulee is a massive canyon system carved when the Columbia River was temporarily diverted southward by glacial ice during the last ice age, and subsequently scoured repeatedly by catastrophic Missoula Floods that swept through the region. The canyon is 50 miles long, up to 900 feet deep, and several miles wide in places, creating a landscape of almost overwhelming scale. The rim trail hugs the edge of the coulee, providing continuous aerial views down to Banks Lake far below and across to the opposite coulee wall, where the basalt stratigraphy is exposed in vivid horizontal layers recording millions of years of volcanic activity. The sage-steppe vegetation along the rim supports a community of shrub-steppe specialists including sage sparrows, loggerhead shrikes, and sagebrush lizards. Wildflowers in spring include desert parsley, phlox, and bitterroot brightening the open terrain. The trail can be combined with the Steamboat Rock Summit ascent for a comprehensive exploration of the park's diverse terrain. Views of Steamboat Rock itself from the rim trail provide a different perspective on the remarkable isolated mesa and its relationship to the surrounding coulee landscape.