At 9,624 feet, Sonora Pass (CA-108) is the second-highest paved pass in California. That ranking alone tells you something, but the number that actually matters on a motorcycle is 26 — the maximum grade, in percent, that greets you on the approach to the summit. This is not a road that flatters inattention. It rewards riders who choose their gears deliberately, brake early, and take time to stop.

Why This Road Exists

The route over Sonora Pass follows almost exactly the same line as the Sonora and Mono Wagon Road, built in 1863–1864 to connect Tuolumne County's Gold Rush towns with the mining districts on the eastern Sierra and into Nevada. Freight wagons and mule trains used these same switchbacks to haul ore and supplies across the range. Today's CA-108 is paved on the same alignment, which is worth keeping in mind when the road tightens up near the summit — the geometry was not designed for anything moving fast.

The Road, Segment by Segment

Sonora to Strawberry (lower foothills): CA-108 leaves the Gold Rush town of Sonora at around 1,800 feet and climbs through oak woodland and small Sierra foothill communities — Twain Harte, Mi-Wuk Village, Cold Springs, Strawberry. The road here is relaxed: moderate curves, reasonable grades, light traffic on weekdays. Use this section to settle into the altitude and the rhythm of the road.

Strawberry to Kennedy Meadows (mid-elevation forest): Elevation rises steadily through pine and fir forest. The USDA Forest Service scenic highway corridor begins in earnest here. About 18 miles east of Pinecrest, pull into Donnell Vista — a quarter-mile accessible trail leads to a cliff-edge overlook above the Middle Fork Stanislaus River Canyon and Donnell Reservoir at roughly 6,300 feet, with the volcanic Dardanelles formation beyond. It is an easy stop to blow past and one worth not blowing past.

Kennedy Meadows to the Summit (the technical section): Above Kennedy Meadows, the road changes character entirely. It becomes steep, narrow, and winding. Grades average 8% but hit 26% on the ramps below the summit — some of the steepest paved road in California. The road surface is generally good, but there are sections without guardrails and with blind corners over ridges. Engine braking matters here. This stretch demands full attention and a clear head about your sightlines.

Summit to Leavitt Meadows (eastern descent): The summit sits at 9,624 feet. The Pacific Crest Trail crosses the highway here, and there is a picnic and parking area. The eastern descent runs through a series of S-curves and two sets of hairpin switchbacks — the final one is signed at 10 mph — before opening into the broad alpine panorama of Leavitt Meadows. Stop at Leavitt Falls Vista Point, about 8.8 miles west of US-395, where a short walk delivers views of Leavitt Falls cascading down granite slabs into the valley below.

Leavitt Meadows to US-395 (eastern run-out): The terrain opens into sagebrush and high desert as elevation drops. The road smooths out as it approaches the junction with US-395 near Bridgeport. Watch for a few sleeper corners in this section; some are signed at 15 mph and easy to misjudge after the drama of the summit.

How to Ride It

This is not a road for new riders or for riders on their first trip into the mountains. The combination of steep grades, tight switchbacks, limited guardrails, altitude-thinned air affecting both engine and rider performance, and sections with genuine blind corners over rises adds up to a road that requires experience and deliberate technique. That said, a touring bike or cruiser handles it well — the road surface on the west side is in good condition, and the west-to-east direction keeps your inside wheel on the uphill side of the switchbacks, which many riders find more predictable.

Traffic is genuinely light compared to Tioga Pass (CA-120) to the south, which draws heavy Yosemite park traffic. Long vehicles are a known hazard on Sonora's switchbacks — they struggle to make the tightest turns, sometimes occupying both lanes. Cell service is patchy from Bridgeport to the pass; download offline maps before you leave.

Ride the pass in the morning when light is best and temperatures haven't built. Even in midsummer, the summit can be cold. Bring a layer.

Season and Closure Window

CA-108 over Sonora Pass is a summer-only road. Caltrans formally closes it each winter — typically in November when snow accumulates — and works to reopen it before Memorial Day, though the actual opening date varies considerably with snowpack. In 2025, the road reopened May 15. In a low-snow year like 2026, Caltrans reopened it April 30, one of the earliest openings on record. The target is always prior to Memorial Day weekend. Once open, late-spring storms can still force temporary closures. Check Caltrans QuickMap before any trip over the pass, especially in May, June, and October.

Early-season riders should expect sand and gravel in the curves from winter plowing operations, and possible ice in shaded sections even after the official opening.

Fuel and Where to Stop

Fuel options on the corridor are sparse. The town of Sonora on the west end is the last reliable fuel before the mountain section. On the east side, Bridgeport on US-395 has gas, though prices run higher than in the valley. Plan your fuel before you start the climb — the corridor between Sonora and Bridgeport has limited reliable services, particularly after the 2018 Donnell Fire destroyed structures in the Dardanelle area.

For views, Donnell Vista on the west side and Leavitt Falls Vista Point on the east side are the two named stops worth building into your schedule.

Plan Your Ride

Sonora Pass works well as a day crossing from the Central Valley to the Eastern Sierra, or as one leg of a multi-pass loop using CA-4 (Ebbetts Pass) or CA-89 (Monitor Pass). Riders exploring california mountain roads often combine this crossing with a run north or south on US-395. Give the road three hours to cross at a relaxed pace with stops — trying to rush it defeats the point and adds risk on a road that is unforgiving of divided attention. Check Caltrans for conditions, fuel up before the climb, and bring a jacket for the summit.