Lonesome Highway — Centennial Range Divide Road to Elk Lake via Red Rock Pass

The Centennial Mountains form one of the sharpest east-west ridgelines in the Northern Rockies, and the two-track that parallels their spine sits directly on the Continental Divide — one tire in Idaho, one in Montana, for miles at a stretch. Red Rock Pass at 7,120 feet is your launching point, where the pavement ends and the BLM dirt begins. The road threads high meadows above the Red Rock Lakes National Wildlife Refuge — a place so remote that trumpeter swans nest here in numbers you won’t see anywhere else in the lower 48. The route climbs to exposed ridgeline benches with views into both the Upper Red Rock Lake basin and the Island Park caldera before dropping to the Elk Lake Resort area west of Yellowstone’s backdoor. Grizzly bear use of this corridor is heavy; this is not casual camping territory.

Rated moderate to difficult depending on conditions — the high meadow sections go soft and rutted after rain and can be impassable in early summer. A lifted 4WD with good ground clearance is the minimum; a locking differential helps on the muddier bench sections. Best run July through September after snowmelt clears the upper elevation crossings. No formal permits required on BLM land, but the Wildlife Refuge sections have closure periods — check Red Rock Lakes NWR before you go. Fuel at Monida or West Yellowstone. Dispersed camping is excellent on the BLM benches. Cell service is flat zero.