Ackerson Mountain
Peak · 5,251 ft · Yosemite corridor
Ackerson Mountain is a 5,251-foot peak in the Yosemite corridor's high Sierra. Low traffic and moderate avalanche terrain make it a backcountry objective for experienced winter and spring climbers.
Wind averages 7 mph over the past month but can spike to 21 mph, especially mid-afternoon when systems move east off the Sierra crest. Temperatures swing from 33 degrees in deep winter to 62 degrees in early autumn. Morning ascents are calmer; afternoon tends toward wind and variable conditions. Snowpack instability requires avalanche awareness in spring.
Over the past 30 days, conditions averaged a NoGo Score of 31 with an average wind of 7 mph and temperature of 45 degrees Fahrenheit. The week ahead shows typical spring variability: watch for afternoon wind spikes and rapid snowmelt affecting approach routes. Winter and early spring are the most wind-prone windows; late September through October offer the most stable and temperate climbing windows.
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About Ackerson Mountain
Ackerson Mountain sits at 5,251 feet in the high Sierra east of Yosemite Valley, roughly between Tuolumne Meadows and Mono Basin. Access typically starts from Highway 120 (Tioga Road), which is seasonal; the road closes in winter. From the Tioga Road corridor, approach times vary depending on snow cover and exact trailhead. The peak sits in designated avalanche terrain; the SAC (Sierra Avalanche Center) monitors this zone. Low base popularity (0.2 on relative scales) means parking and crowds are rarely issues, but isolation also means self-rescue and winter navigation skills are essential.
The past 30 days show an average temperature of 45 degrees Fahrenheit and average wind of 7 mph, though gusts reach 21 mph regularly. Over a full year, temperatures range from 33 degrees (winter) to 62 degrees (autumn). Ackerson Mountain sits above the inversion layer that can trap cold air in Yosemite Valley, so expect milder overnight lows than lower elevations on clear nights. Spring snowmelt accelerates in mid-morning as solar radiation increases; approach routes degrade through the afternoon. Winter approaches require careful avalanche assessment; the terrain has multiple gullies and steep slopes that slide under loaded or corn conditions.
Ackerson Mountain suits experienced mountaineers comfortable with avalanche terrain, off-trail navigation, and self-sufficiency. Parties typically climb in late spring (April through early June) when snowpack consolidates but summer dry conditions have not yet begun. Winter ascents demand avalanche certifications and stable weather windows. Late September through October offer temperate conditions (averaging 45 degrees in that window historically) and lower wind risk than spring. The base popularity of 0.2 reflects true backcountry status; expect no established parking areas, limited cell service, and potential weather exposure during rapid systems. Solo travel is not recommended due to terrain complexity and isolation.
Nearby alternatives include peaks along the Tioga Road corridor and the higher summits near Tuolumne Meadows. Ackerson Mountain's advantage is its compact, low-traffic character compared to popular Yosemite Valley approaches. Winter climbers preparing for high Sierra objectives sometimes use Ackerson as a shakedown climb. The peak's avalanche terrain is moderate relative to the highest Sierra crests but requires the same respect; early-season ascents (late spring) when corn conditions stabilize reward early mornings and discourage afternoon attempts when surface melt weakens slopes.