The Long Pines are a small mountain range in southeastern Montana, southeast of Ekalaka, rising to about 4,094 feet near the Montana–South Dakota border. They are closely linked with the Ekalaka Hills and the East and West Short Pine Hills, forming a distinct group of isolated uplands in an otherwise open landscape. Long Pines is also the present name of a former national forest later absorbed into Custer Gallatin National Forest. The current Long Pines land unit covers 70,969 acres, mostly in Carter County, Montana, with a small extension into Harding County, South Dakota, and is administered within the Sioux Ranger District.