In 1935 the national forest reached its maximum size of 1,026,329 acres ( 4,105 km2 ) .
The U.S. federal government established the Ottawa National Forest in 1931 , but the forest did not reach its full size until after two large land purchases in 1933 and 1935 .
In 1935 the national Ottawa National Forest reached Ottawa National Forest 's maximum size of 1,026,329 acres ( 4,105 km2 ) .
The U.S. federal government established the Ottawa National Forest in 1931 , but the forest did not reach its full size until after two large land purchases in 1933 and 1935 .