National grassland

A national grassland is an area of protected and managed federal lands in the United States authorized by Title III of the Bankhead–Jones Farm Tenant Act of 1937 and managed by the United States Forest Service.

For administrative purposes, they are essentially identical to national forests, except that grasslands are areas primarily consisting of prairie.

Those four are in southeastern Idaho, northeastern California, central Oregon, and a reserve in Illinois.

[1] The catastrophic Dust Bowl of the 1930s led to the creation of the Soil Conservation Service in 1933.

The smaller Midewin National Tallgrass Prairie, created much later and east of the Mississippi River, is technically not a "National Grassland", as it was formed under different legislation, but it is managed by the Forest Service like one, as a unique prairie resource.