Mammoth Pass
Peak · 9,383 ft · Yosemite corridor
Mammoth Pass, a 9,383-foot peak in the Yosemite corridor of California's Sierra Nevada, sits exposed to afternoon wind funnels off the high country. Winter approach requires avalanche terrain awareness.
Wind accelerates through the pass by mid-afternoon, averaging 11 mph over the last 30 days with gusts to 31 mph. Cold persists year-round; the 30-day mean is 31 degrees Fahrenheit. Morning calm is reliable; afternoon exposure is not.
Over the last 30 days, Mammoth Pass averaged a NoGo Score of 34.0, with temperatures holding at 31 degrees Fahrenheit and wind averaging 11 mph. The week ahead follows the same exposure pattern: expect stronger gusts in the afternoon hours and consistently low temperatures. Plan for pre-dawn or early-morning activity if wind sensitivity matters.
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About Mammoth Pass
Mammoth Pass sits at 9,383 feet on the eastern slope of the Sierra Nevada within the Yosemite corridor. Access is via Highway 395 from the south (Mammoth Lakes) or Highway 120 from the west (Yosemite Valley). The pass forms the drainage divide between the Mono Basin and the Sierra crest. It is a high-altitude crossing prone to winter closure; Highway 120 (Tioga Pass) typically opens in late May after snowmelt and spring maintenance. The pass receives winter and spring traffic from skiers, mountaineers, and climbers approaching the east Sierra peaks.
Conditions at Mammoth Pass shift sharply with season. Winter snowpack creates avalanche terrain; the pass lies within SAC (Sierra Avalanche Center) advisory coverage and requires careful assessment of slope stability before travel. The 30-day average temperature of 31 degrees Fahrenheit reflects the zone's persistence cold from late autumn through spring. Wind averages 11 mph with gusts to 31 mph, most intense in afternoon hours when thermal circulation strengthens. Summer brings relief: temperatures climb to the 40s Fahrenheit, wind moderates slightly, and crowding (averaging 3.0 on the rolling 30-day measure) remains low because the pass is a transit point, not a destination.
Mammoth Pass suits climbers and ski mountaineers with experience in high-altitude avalanche terrain. Hikers and summer day-trippers use it as a passage between Highway 395 and Yosemite Valley. The pass is not a recreational hub; it is a conduit. Visitors plan around closure windows (winter and early spring), afternoon wind (expect exposure if crossing after 11 a.m.), and early-season snowpack hazards. Parking is minimal; approach is typically as part of a longer valley or peak traverse. The pass is coldest and most hazardous from December through April; stable travel windows open in late May and persist through September.
Nearby alternatives include Tioga Pass (the main Highway 120 crossing, lower traffic intensity), Tenaya Lake (a winter-calmer water access point west of the pass in Yosemite), and the peaks north of the pass (Cathedral Range) which see comparable exposure but higher visitation. Mammoth Pass is less famous than Tioga Pass but sits on the same climate and avalanche gradient. Experienced high-Sierra travelers choose between the two based on spring snowpack conditions and wind forecasts rather than season alone.