Sight Unseen: How Frémont's First Expedition Changed the American LandscapeJohn C. Fr mont was the most celebrated explorer of his era. In 1842, on the first of five expeditions he would lead to the Far West, Fr mont and a small party of men journeyed up the Kansas and Platte Rivers to the Wind River Range in Wyoming. At the time, virtually this entire region was known as the Great Desert, and many Americans viewed it and the Rocky Mountains beyond as natural barriers to the United States. After Congress published Fr mont's