Highway 172, Mineral Summit, CA

Highway 172 on the south side of Mount Lassen is a 9-mile loop that’s more than just a bypass; it’s one-lane joy ride back in time.

Stretching from the small community of Mineral to Morgan Springs, Highway 172 is actually the original alignment of Highway 36. Long before the modern bypass was built, this was the primary route for travelers heading east from Red Bluff. The road’s history is rooted in the 1860s Humboldt Road, a rugged wagon route that once served as a lifeline between the Sacramento Valley and the mining camps of the Sierra Nevada.

The highlight of the loop is crossing Mineral Summit. At an elevation of approximately 5,272 feet, the summit offers a tighter, single lane, experience than the sweepers on the main highway. Eastbound out of Mineral, the road narrows significantly, following the gentle curves of Mill Creek through undulating swoopy curves that’s “motorcycle paradise” that feels worlds away from the Highway 36 up and over Mount Lassen past the entrance to the national park traffic to the north.

Highway 172 is the perfect detour off the main highway and pops out back onto Highway 36 at Childs Meadow.