Pinesdale is nestled between the Bitterroot River and the Bitterroot Mountain Range. St. Mary's Mission and Fort Owen are two of Montana's earliest settlements, to the north. The Bitterroot Mountains form a rugged, glacier-carved border between Idaho and Montana. On both sides of this border is the Selway-Bitterroot Wilderness. This 1.3-million-acre wilderness has peaks that rise up to 10,157 feet and over 1,490 miles of trails creating a haven for backpackers, hikers, stock users and outdoor adventurers alike.