Land

The Great Plains form the eastern third of Wyoming with the Rocky Mountains covering the rest of Wyoming. Much of western Wyoming constitutes a special geomorphic province known as the Wyoming Basin. The Wyoming Basin separates the Middle and Southern Rockies. Extending diagonally across the state from northwest to south is the Continental Divide, which separates the generally eastward-flowing drainage system of North America from the westward-flowing drainage of the Pacific states.

Wyoming's mean elevation is 6,700 ft (2,044 m), 2nd only to Colorado's among the 50 states. The highest point of the state is Gannett Peak, in western Wyoming, at a height of 13,804 ft (4,210 m). The lowest point in the state is on the Belle Fourche River at a height of 3,099 ft (945 m).

Wyoming's largest lake—Yellowstone—lies in the heart of Yellowstone National Park. Jackson and Jenny, two smaller lakes lies in Grand Teton National Park. All but one of Wyoming's major rivers originate within its boundaries and flow into neighboring states. The Green River flows into Utah; the Yellowstone, Big Horn, and Powder rivers flow into Montana; the Snake River, into Idaho; the Belle Fourche and Cheyenne rivers, into South Dakota; and the Niobrara and Bear rivers, into Nebraska. The only exception is North Platte River, enters Wyoming from Colorado and eventually exits into Nebraska.