Lonesome Highway — Centennial Road to Challis via the White Cloud Peaks Backdoor

FR 086 up Patterson Creek off US-93 north of Mackay is one of those roads that most people drive past without a second glance — which is exactly why it’s worth turning in. The route climbs from the broad Lost River Valley floor into a tight creek canyon flanked by fault-block ridges rising toward the White Cloud Peaks Wilderness to the west, eventually topping out on a sage-covered bench before dropping into the Salmon River drainage toward Challis. The road is maintained gravel for the first several miles before transitioning to rougher two-track through lodgepole and open mountain shrub. Expect creek crossings of Patterson Creek itself — typically knee-to-axle deep in early summer, manageable by late July.

This isn’t a technically extreme route, but its remoteness is real — you’re two-plus hours from any meaningful services once you leave US-93. A stock 4WD with adequate ground clearance handles it fine in dry conditions; the creek crossings and loose shale sections on the upper bench deserve respect in a two-wheel drive. Best season is July through September; the upper bench can hold snow into late June and gets slick mud in early season. Fuel in Mackay before you go — Challis has a station at the far end. No permit required. Dispersed camping is open throughout the Challis National Forest sections. Cell service disappears before the first creek crossing and doesn’t return until the Salmon River canyon near Challis.