Squaretop Mountain, Wind River Mountains, Wyoming

In this Black & White photograph, 11,695-foot Squaretop Mountain, a small remnant of a once vast granitic plateau, looms above the headwaters of the Green River, one of the great rivers of the West. During the Pleistocene epoch, enormous glaciers, thousands of feet thick, carved valleys on both sides of this mountain to create its unique profile. Two cerulean-hued lakes collect the first waters of the Green below Squaretop as it begins its long journey through the canyons of the southwest. By the time this great river reaches the Sea of Cortez, dams and diversions have reduced its flow so much that it usually dies in the sands of its delta before reaching the sea.