 As of September 30, 2008, Whitman had an area of , representing 55.96% of the combined forest's .Wallowa National Forest

Wallowa National Forest was first established as the Wallowa Forest Reserve in Oregon on May 6, 1905 with .On March 1, 1907 it was combined with the Chenismus Forest Reserve to create Imnaha National Forest, which was then renamed Wallowa on July 1, 1908.