Sonora Pass (CA-108)

CA-108 crosses the Sierra Nevada over Sonora Pass, linking the Central Valley foothills to the Eastern Sierra via steep grades and high-elevation scenery, with the road typically closed in winter.

CA-108 over Sonora Pass is one of the steeper paved crossings in the Sierra Nevada, and that's the point. Grades hit around 26% on the eastern approach — sustained, not just a brief pitch — combined with tight switchbacks and significant elevation gain. For riders on heavier touring bikes, this is actually a better technical crossing than some of the more famous Sierra routes, because the road stays relatively uncrowded and the pace is set by the terrain rather than by traffic. You earn the views here.

The eastern side of the pass is where the road demands the most attention. Coming up from the high desert, the switchbacks are short-radius and the grade is relentless. Loose gravel migrates to the outside of turns, particularly after weather or wind events, and the elevation — the pass sits above 9,600 feet — means thin air affects both you and the engine. Take the climb at a pace that lets you stop cleanly. The western descent is less severe but still deliberate, dropping through open subalpine terrain before the canyon begins to close in.

Once you're down into the mid-elevation stretch, the character changes. The Brightman Flat Campground area marks where the canyon starts to feel like a canyon, with rock walls, timber, and a creek corridor shaping the road. Through Strawberry, the Strawberry Inn is a reliable stop — food and a place to pause before the road flattens out further toward the foothills. The towns of Bumblebee and Cow Creek are small reference points rather than destinations, but useful for orienting yourself on the descent. Below Strawberry the road loses elevation steadily, trading the high Sierra feel for oak-covered foothill terrain.

The full run from the eastern junction at US-395 to the western foothills covers around 77 miles if you're doing the complete crossing. The 63-mile figure reflects a partial segment, so plan your fuel accordingly — services are sparse on the eastern side, and there's a long stretch between the pass and anything resembling a town. Top off before you start the climb from either direction.

Before you go: CA-108 over Sonora Pass is a seasonal road. It typically closes sometime in November and reopens in late spring — late May is a reasonable expectation, but snow year to year determines the actual dates. Check Caltrans road conditions before committing to the route, especially in shoulder seasons. The high elevation means afternoon thunderstorms are possible in summer, particularly July and August. If clouds are building over the ridge when you're in the valley, get over the pass early.

CA-108 earns its reputation on the east side of the pass, where the road climbs to 9,624 feet through a series of tight switchbacks on grades that regularly hit 26 percent — some of the steepest paved road in California. That pitch means you're working through slow, technical corners with significant elevation change in a short stretch, not flowing sweepers. The west side is more gradual, with longer curves through pine forest and river canyon before the terrain opens up.

The high country around the pass itself is volcanic and mostly treeless — exposed ridgelines, remnant snowfields well into summer, and views across the Central Sierra that are specific and stark rather than lush. It reads differently from the granite scenery on Tioga Pass (CA-120) to the south: rawer, less polished, and noticeably less trafficked.

That lower traffic is part of why riders seek it out. On a weekday in September, you may share the road primarily with a few hikers' cars and the occasional cattle truck rather than the RV convoys that clog other trans-Sierra routes.

The road also connects well if you're stringing together an Eastern Sierra loop — it drops you onto US-395 near Bridgeport, which puts Walker and the canyon roads to the north within easy reach.

Before you go: The pass typically opens in late May or June and closes at the first significant snowfall, often October. Check Caltrans road conditions before committing — the window can be short in a heavy snow year. The east-side switchbacks collect gravel and debris near the edges after any weather; stay off the margin on those descending corners. Cell coverage is minimal from roughly the summit down to the US-395 junction. Fuel up in Sonora or Bridgeport; there's nothing reliable mid-route. Deer and cattle crossings are common at dawn and dusk.

// Why this road