Casa Diablo Mountain
Peak · 7,887 ft · Eastern Sierra corridor
Casa Diablo Mountain is a 7887-foot peak in the Eastern Sierra's high-altitude corridor, exposed to sustained westerly wind and snow cover through spring. Expect raw conditions and solitude.
Wind averages 13 mph but regularly gusts to 39 mph, funneling up the eastern face by mid-afternoon. Morning calm is brief. Temperature swings 20 degrees between shade and sun exposure. Avalanche terrain demands winter awareness; snowpack persists through late spring.
Over the past month, Casa Diablo averaged a NoGo Score of 36 with temperatures holding at 42 degrees Fahrenheit and wind at 13 mph. The 30-day maximum wind reached 39 mph. This week ahead remains typical for the season; plan morning ascents and monitor afternoon wind buildup. Spring snowpack is active; assess slope angle and recent loading before committing to steep terrain.
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About Casa Diablo Mountain
Casa Diablo Mountain sits on the eastern flank of the Sierra Nevada, due east of Mammoth Lakes and southwest of Mono Basin. The peak rises above high-desert scrub and sparse lodgepole forest. Access is via Highway 395; from Mammoth Lakes, drive north on 395 for roughly 20 minutes to the Casa Diablo area turn-off. The trailhead is unsigned and parking is informal; arrive before mid-morning if visiting weekends. No developed facilities exist; bring water and be self-sufficient.
Conditions here are dictated by elevation and exposure. The 30-day average temperature of 42 degrees reflects typical spring conditions; yearly minimums drop to 21 degrees in winter, maximums reach 57 degrees in late summer. Wind is the dominant constraint: the 30-day average is 13 mph, but gusts spike to 39 mph, driven by westerly flow funneling through the Sierra crest and deflecting east. Afternoon builds are relentless. Crowds are minimal; the 30-day crowding average is 2, indicating single-digit parties most days. Early-season snow closes safe approach routes until June.
Casa Diablo is suited for experienced mountaineers and ski-mountaineers comfortable with avalanche terrain and sustained wind exposure. The low base popularity (0.2) and minimal crowding reflect the peak's reputation for difficulty and remoteness. Winter and early-spring visitors must assess snowpack, recognize loaded slopes, and carry rescue kit. Summer brings exposed rock scrambling and exposure to afternoon thunderstorms. A 30-day minimum NoGo Score of 4 and maximum of 65 indicate that windows do open, but they are brief and demand morning execution.
Casa Diablo anchors a cluster of remote Sierra peaks reachable via Highway 395. Nearby Mono Basin offers lower-elevation weather observation and supply stops. Mammoth Lakes provides lodging and serves as the primary gateway. The Eastern Sierra Avalanche Center (ESAC) maintains forecast bulletins; consult before any winter or spring venture. Compare conditions here to more sheltered options like Convict Lake or Dry Creek if afternoon wind or spring avalanche hazard becomes limiting.