Beginning at the Montana border, atop Lost Trail Pass, US-93 winds steeply downhill through the 4.3-million-acre Salmon-Challis National Forest. Another 25 miles south of the pass, US-93 passes by the village of North Fork—where the friendly folks at the North Fork General Store (208/865-7001) run a combination café, motel, and post office that has everything a traveler could want, from great pies to an RV park. Here US-93 crosses the Salmon River, which is often called the “River of No Return,” because without a jet boat to help you along, it is navigable only in a downstream direction. Running swiftly for nearly 300 miles west through one of the most extensive wilderness areas left in the lower 48 states, the Salmon River has carved one of the deepest gorges in North America, a full 1,000 feet deeper than the Grand Canyon.

From North Fork, a paved road leads 18 miles west along the riverside to the tiny hamlet of Shoup, beyond which a number of rough roads and hiking trails lead to ghost towns and the Frank Church-River of No Return Wilderness, deep in the rugged mountains.