Colby Pass
Peak · 11,991 ft · Eastern Sierra corridor
Colby Pass is an 11,991-foot Sierra crest pass in the Eastern Sierra corridor, approached from the Inyo National Forest side. Sits well above tree line with minimal shelter from wind.
Wind channels hard through the pass most afternoons, averaging 11 mph with gusts to 31 mph. Morning hours offer the calmest conditions before thermals drive air up the eastern slope. Expect rapid temperature swings as cloud cover changes; the 30-day average sits at 23 degrees Fahrenheit.
Over the past 30 days, Colby Pass averaged a NoGo Score of 38.0 with temperatures holding at 23 degrees Fahrenheit and wind running 11 mph on average. The week ahead will likely track similar patterns; watch for afternoon wind ramps and any warming trend that could destabilize the remaining snowpack in the surrounding terrain.
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About Colby Pass
Colby Pass straddles the Sierra crest at 11,991 feet on the boundary between Mono and Inyo counties. The pass lies north of the Whitney Portal area and sits within the Eastern Sierra corridor, accessed primarily from the Inyo National Forest via the Cottonwood Lakes trailhead near Lone Pine. Highway 395 runs the length of the eastern front; Lone Pine is the primary gateway town, roughly 10 miles south of the pass's road-accessible base. The pass marks a key saddle on the high country ridge; winter and early spring routes cross via steep snow ramps that demand avalanche awareness.
Colby Pass sits in the rain shadow of the High Sierra, so precipitation falls as snow above 10,000 feet from late fall through early spring. The 30-day average wind of 11 mph masks afternoon acceleration; sustained thermals push flow hard between 2 p.m. and dusk. Temperature swings from morning lows near 5 degrees Fahrenheit to afternoon highs around 36 degrees Fahrenheit are common across the full year cycle. Crowding remains minimal year-round, averaging 2.0 on the nogo scale, because access is technical and seasonal. Snow typically blocks direct passage from November through May; the pass opens reliably only after July when the east slope is ski-free.
Colby Pass suits experienced mountaineers and backcountry skiers who plan around avalanche terrain and exposure. Winter approaches demand current avalanche bulletins from the Eastern Sierra Avalanche Center; the surrounding slopes hold persistent weak layers that can propagate slab failures. Summer visitors rely on scrambling and off-trail boulder hopping; route-finding is complex above tree line. Afternoon wind gusts to 31 mph make mid-day exposure unpleasant; early starts and morning departures are non-negotiable. Parking at the Cottonwood Lakes trailhead fills on clear weekends but rarely during the week.
Nearby Muir Pass to the north and Kearsarge Pass to the south offer lower-elevation alternatives with similar crest-crossing exposure but more modest avalanche terrain. The high country between Colby and Whitney Portal forms a continuous ridge system; Colby sits well above the popular Whitney trail corridor. Visitors drawn to the Eastern Sierra's glacial lakes and granite peaks find Colby Pass a seldom-visited scramble with genuine summit character and unobstructed views across the Inyo Basin.