The Middle Fork Trail #4001 begins at the Middle Fork Transfer Camp & Trailhead, which offers toilet facilities, stock holding facilities, a ramp, and long-term parking for boaters and hikers.

This trail provides the major land-based access into the Middle Fork Salmon River corridor within the Frank Church River of No Return Wilderness, extending to Impassible Canyon and allowing foot and horse travel.

Users should be prepared for rock fall, downed trees, and potential spring flooding, and must follow Leave No Trace ethics and wilderness regulations including fire pans and pack-out requirements.