Sonora Pass, at 2,933 metres, is the second-highest highway pass in the Sierra Nevada, beaten only by Tioga Pass in Yosemite, and it may well be the most demanding. On the approach from the west the road climbs steeply over open slopes of volcanic rock, with long views back down into the Stanislaus canyon, and the final kilometres are a series of tight, steep switchbacks with gradients that reach well into the double digits. On the eastern side the descent toward the Walker River is even steeper, with signs warning of grades of up to 26 per cent in places.
The summit itself is a barren saddle of reddish and grey volcanic rock, with patches of snow lingering well into July and alpine flowers in the cracks. The Pacific Crest Trail crosses here, and hikers sometimes camp near the parking area. Look north and south and the jagged peaks of the Sierra run off into the distance, and to the east the land drops away toward the high desert of Nevada.
The road was built as a wagon route in the 1860s, following an old path used by the Washoe and other native peoples, and it remained a rough track for decades. Even today it is narrow and unforgiving, with no guardrails in some places and frequent rockfall. Ride it in good weather, preferably in the morning, and be prepared for sudden changes. Afternoon thunderstorms are common in summer, with hail and lightning, and the temperature at the top can be very low even on a hot day.
On the eastern descent, the road passes the Marine Corps Mountain Warfare Training Center near Pickel Meadow, where Marines train for mountain and cold-weather operations. You may see military vehicles on the road. Further down, Leavitt Meadows and the West Walker River offer pleasant places to stop.
The pass itself sells nothing but the view. The road is closed in winter, usually from November to late May or early June, depending on snow. The nearest town with fuel on the east side is Bridgeport, about thirty-five kilometres away, a small town with a courthouse and a few motels. Make sure your brakes are in good condition and that you have enough fuel before attempting the crossing.