Cooper Peak
Peak · 9,557 ft · Yosemite corridor
Cooper Peak is a 9,557-foot summit in the Yosemite corridor of California's Sierra Nevada. Alpine exposure and sustained afternoon wind make this a technical destination for experienced mountaineers.
Wind averages 9 mph but gusts to 24 mph; afternoon funneling is the norm. Early morning calm is brief; skip the approach after 11 am unless you're confident in alpine conditions. Temperature hovers near 34 degrees on the 30-day average. Avalanche terrain dominates the approach.
The 30-day average wind of 9 mph masks significant afternoon acceleration; gusts reach 24 mph regularly. Temperature on the rolling 30-day average sits at 34 degrees Fahrenheit, well below the 49-degree high typical in warmer months. Crowding averages 3, indicating sparse foot traffic even in spring. The week ahead mirrors recent conditions: morning windows narrow as alpine heating drives wind upslope by midday.
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About Cooper Peak
Cooper Peak sits at 9,557 feet on the eastern flank of the Yosemite corridor, roughly 30 miles east of Yosemite Valley via Highway 120 and accessed from the Mono Basin approach. The peak straddles high-Sierra terrain east of the Cathedral Range. Primary access runs through Mono County gateways; Highway 395 feeds the eastern approach. The summit is exposed alpine terrain with no protection from westerly flow or thermal wind development. Elevation and exposure make this a mountaineering objective rather than a casual hike.
Alpine conditions dominate year-round. The 30-day average temperature of 34 degrees reflects the season's lingering winter chill; annual extremes range from 24 to 49 degrees Fahrenheit. Wind averages 9 mph but consistently gusts to 24 mph, particularly in the afternoon when solar heating drives air upslope. The rolling 30-day NoGo Score averages 32, meaning stable conditions are rare; scores range from 6 (brief calm mornings) to 50 (full windstorms). Crowding remains sparse at an average of 3, typical of remote high-Sierra peaks. Spring snowpack lingers into late summer; avalanche terrain assessment via the Sacramento Avalanche Center is mandatory.
This peak suits experienced alpinists with solid rock scrambling and self-rescue skills. High wind exposure demands early starts; head for the summit before 10 am to avoid afternoon gusting. Late spring and early summer (late May through July) offer the best windows between snow retreat and peak summer wind. Parking is limited at trailheads on the eastern approach; arrive before dawn. Bring a windproof shell, extra layers, and a head torch for early departure. The sparse crowding (3 average) means you'll likely be alone, a relief for exposed scrambling but risky if injury occurs.
Nearby Cathedral Peak and Mount Dana offer similar alpine exposure and marginally better shelter from the prevailing west wind. Mount Dana (11,056 feet) is slightly higher but warmer due to its position south of the Cathedral Range crest. Mono Basin lakes at lower elevation provide warming overnight stops if tackling a two-day push. The Yosemite corridor as a whole sits exposed to Pacific frontal systems; Cooper Peak is neither the most nor least protected, but the 9 mph average wind and 24 mph gusts demand respect. Solo climbers should consider linked objectives with other peaks to minimize return trips through exposed terrain.