Clarks Fork Yellowstone River
 The Clarks Fork Yellowstone River (sometimes called the Clarks Fork River) is a tributary of the Yellowstone River 150 mi (241 km) long in the U.S. states of Montana and Wyoming.It rises in southern Montana in the Gallatin National Forest in the Beartooth Mountains approximately 4 mi (6 km) northeast of Cooke City and southwest of Granite Peak. It flows southeast into the Shoshone National Forest in northwest Wyoming east of Yellowstone National Park then northeast back into Montana.