Wind River Range

From Union Pass, the eye can follow the Continental Divide to Union Peak, about four airline miles away but nearly six by the tortuous route, and then to Three Waters Mountain, seven miles farther along the divide. Beyond that visible reach lie Gannett Peak and Fremont Peak, marking the heart of the Wind River Range. The Wind River Range is the highest mountain mass in Wyoming, a broad uplift formed about 60 million years ago during the Laramide Orogeny. Its core exposes Precambrian crystalline rocks, while Paleozoic and Mesozoic sedimentary rocks are upturned on its flanks. Although south of continental ice caps, the range was extensively glaciated during the Pleistocene epoch, and sizable lakes such as Newfork, Boulder, Fremont, Bull, Green River, and Dinwoody occupy canyons and valleys along its flanks behind moraines. The surviving glaciers in the highest parts are small by comparison, yet are often cited as the largest ice fields within the contiguous states. Boulders scattered around Union Pass show that the northern margin of the range was subdued by spreading glaciers that left a blanket of till and moraine material.

Wyoming · United States