North Fork Diversion Reservoir
Lake · Yosemite corridor
North Fork Diversion Reservoir sits at 6755 feet in the Yosemite corridor's high Sierra, a modest alpine lake fed by snowmelt and protected from the worst afternoon winds by surrounding ridgeline.
Wind averages 6 mph but can spike to 20 mph by mid-afternoon as thermals drain the drainage. Morning hours are markedly calmer. Cold water and exposure mean conditions deteriorate fast once sun angles drop. Head before 11 a.m. for the flattest conditions.
Over the last 30 days, the NoGo Score averaged 14, with temperatures holding near 35 degrees Fahrenheit and wind averaging 6 mph. The week ahead shows continued spring volatility. Expect scores to swing between 6 and 27 depending on wind timing and snowmelt runoff. Use the chart to catch low-wind windows, typically early in the day.
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About North Fork Diversion Reservoir
North Fork Diversion Reservoir lies on the North Fork Merced River drainage in California's high Sierra, approximately 15 miles northeast of Yosemite Valley via Highway 120. The reservoir serves as a water-management feature on the eastern approach to the park corridor, sitting well above the Valley floor and closer to the crest than to the valley bottom. Access is via Highway 120; the nearest gateway is Lee Vining to the east or Yosemite Village to the west. The lake is less trafficked than reservoirs closer to the Valley, making it a quieter alternative for spring and early-summer exploration when Highway 120 is open.
Spring conditions at North Fork Diversion Reservoir are driven by rapid snowmelt and high-altitude wind funneling. Temperatures average 35 degrees over the past month; expect lows near 23 degrees and highs around 51 degrees across a full year at this elevation. Wind averages 6 mph but gusts to 20 mph by afternoon as the sun heats the drainage. The reservoir experiences two distinct daily patterns: calm, glassy water from sunrise to mid-morning, then increasing chop as thermals develop. Crowding is light year-round, averaging 6 on a 10-point scale, meaning solitude is the norm except during major holiday weekends immediately after Highway 120 opens. Late-season snow can linger near the lake through early summer.
North Fork Diversion Reservoir suits paddlers, anglers, and photographers seeking high-altitude conditions without the crowds of larger reservoirs. Kayakers and canoeists should plan for morning launches; afternoon wind makes return paddling exhausting and potentially unsafe. The lake's cold water and exposure to sudden temperature swings demand appropriate gear and weather discipline. Anglers targeting trout appreciate the minimal fishing pressure. The location works best for self-directed visitors who monitor wind timing and are comfortable with primitive access and few facilities. Snow closure is a real risk through early summer; confirm Highway 120 status before committing.
Nearby alternatives include Tenaya Lake and Ellery Lake on the Highway 120 corridor, both larger and more exposed but with better infrastructure. Tioga Lake sits just east at similar elevation but experiences stronger afternoon wind. For a lower-elevation, more sheltered option, Yosemite Valley lakes like Mirror Lake offer gentler conditions but substantially higher crowds. North Fork Diversion Reservoir's value lies in its combination of solitude, accessibility via Highway 120, and morning-friendly wind patterns; it suits visitors who understand high-altitude variability and prefer early starts over midday convenience.