Steens Mountain is the county's most prominent geographical feature, rising to above sea level and spanning many miles across a region that is otherwise fairly flat. To its southeast is the Alvord Desert—the driest place in Oregon—and the Trout Creek Mountains, which extend south into Nevada. South of Steens Mountain, the Pueblo Mountains are another remote range in Oregon and Nevada. North of Steens Mountain lies the Harney Basin, which contains Malheur Lake and Harney Lake.