The Double Mountain Fork Brazos River is an ephemeral, sandy-braided stream about 170 mi (280 km) long, heading on the Llano Estacado of West Texas about 11.5 mi (18.5 km) southeast of Tahoka, Texas, flowing east-northeast across the western Rolling Plains to join the Salt Fork, forming the Brazos River about 18 mi (29 km) west-northwest of Haskell, Texas.

[3] The Double Mountain Fork Brazos River begins as a shallow draw near the eastern edge of the Llano Estacado in Lynn County, about 3.1 mi (5 km) northeast of the small farming community of Draw, Texas.

The stream generally runs eastward across southern Garza County, where it is fed by springs, providing a minimal base flow that is intermittently punctuated by rainfall and associated runoff.

To the east of Double Mountains, the Double Mountain Fork flows into western Haskell County before turning north and back westward into eastern Stonewall County, where it merges with the Salt Fork to form the Brazos River (proper), northeast of Aspermont, Texas.

The stream described here, however, is the main stem of the Double Mountain Fork Brazos River and, therefore, it is not a tributary of the Double Mountain Fork, rather it is a tributary of the Brazos River.