Sioux National Forest

Sioux National Forest was a United States National Forest established by on July 1, 1908. The order called for the consolidation of the following national forests and forest units into a single entity:

On January 13, 1920, Sioux NF was absorbed by Custer National Forest. Although the name Sioux was discontinued as a national forest designation, Custer NF created the Sioux District, which comprised the eight land units of the Sioux NF.
In 2014, Custer National Forest merged with Gallatin National Forest to form Custer Gallatin National Forest. Within this new entity, Custer NF's Sioux District was replaced by the Custer Gallatin NF Sioux Ranger District, which encompasses the Chalk Buttes, Ekalaka Hills, Long Pines, North Cave Hills, South Cave Hills, East Short Pine Hills, West Short Pine Hills, and Slim Buttes land units.