Say Sonora Pass to a Californian rider and watch for the pause. At 2,933 metres it is the second highest road over the Sierra Nevada, after Tioga, and it has a reputation for its gradients: the stretches on the eastern side are rated at around twenty-six percent, which is the sort of number that makes you check your clutch cable. Lanes are narrow, guard rails are rare and the edges are dramatic. It is not the place to try your first mountain pass, but it is a wonderful one to graduate to.
The western approach climbs in long, steady sweeps from the Stanislaus canyon, through fir forest and then into open granite country with big volcanic cliffs hanging above. Near the top the trees thin, the air chills and the road squeezes through a gap between two pale ridges. The summit is a simple saddle with a sign, a gravel pull-out and a view that looks like the end of the world. On the eastern side the road drops in a series of tight hairpins and steep descents toward the Walker River, with the Great Basin spreading below like a map. Trailers longer than about twenty-five feet are banned, and no one with a caravan should be tempted to try.
The pass takes its name from the Mexican miners from Sonora who flooded into the foothills during the Gold Rush, and gave their name to the foothill town on the western side. A wagon road crossed the summit in the 1860s, linking the gold camps with the Nevada silver towns. The Pacific Crest Trail crosses the road close to the top, and walkers often camp in the meadows nearby. A little further down the east side, the Marine Corps runs a mountain warfare training centre, which accounts for the occasional convoy and the sound of helicopters.
The road is open only in summer, typically from late May or June until the first snow in October or November, and there is almost nothing along it. Bridgeport, about 36 kilometres from the summit on the Nevada side, is the nearest real settlement, with fuel, a courthouse and a couple of places to eat, and Sonora is the large town on the western side. Check fuel before leaving either, carry layers, and start early, since afternoon thunderstorms are routine. The best light comes late in the day, as the sun drops behind the crest and the eastern slopes turn gold.