Races
Lake Sonoma 50 Miler
Lake Sonoma loop. Wine country ridges above the reservoir. Fast enough to chase a Western States slot if the heat cooperates.
50 mi14 hours223 ft to 1,158 fttech 9/10Checkpoints per race bookWestern States qualifierwine countrysingle loopApril
Distance50 mi
Altitude223 ft to 1,158 ft
Technicality9/10
Air45°F to 85°F
- Start223 ft
- High1,158 ft
- Low223 ft
- Finish223 ft
- Mid loop at mile 25, cutoff 8 hours
- Finish Lake Sonoma at mile 50, cutoff 14 hours
Field, 2024 · 17-year sampleresults
Starters157
Finish rate100%
Median12:33
Sub-24157
Geometrycourse math
Steepest drop666 ft-6.7% over 1.9 mi
Course records
Men5:51:16Jim Walmsley
Women7:08:23Stephanie Howe
The cruxDam climb mid-race when the sun hits exposed ridges (near mile 33)
Course DNA
The Course
Lake Sonoma 50 Miler runs 50 mi through Lake Sonoma, California. Surfaces skew 75% singletrack / 25% dirt road. Dam climb mid-race when the sun hits exposed ridges. High point near 1,158 ft. Low near 223 ft. April temps run 45°F to 85°F. The course rewards patience early and punishes rushed descents after mile 25.
The Work
Train for the climbing across 50 mi. Back-to-back long runs on similar surfaces. Practice power-hiking grades above 15 percent. 14 hours total means limited margin: rehearse fueling every 45 to 60 minutes and downhill eccentric work weekly. Technicality 9/10. Build a block that simulates the crux near mile 33.
Kit
April in Lake Sonoma, California: plan for 45°F to 85°F. Mandatory shell if rain is in forecast. Headlamp with spare batteries if 14 hours pushes past dark. Poles help on sustained climbs above mile 13. Vest capacity for 2 liters minimum. Shoes matched to 75% singletrack: lugs for mud, rock plate if the course turns technical after mile 25.
Race Day
Hold effort through mile 13. The field often splits on the first big climb after mile 25. Dam climb mid-race when the sun hits exposed ridges near mile 33 is where time is won or lost. Walk the steep pinches. Run the flats and gentle downhills. Crew at major aids: socks, calories, ice if hot. Transitions under 5 minutes when possible. Final third is 17 miles of fatigue management. Finish with reserve for the last descent.
Results
Lake Sonoma 50 Miler finish lines.
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Sources (3)
- Field stats (2024): https://ultrasignup.com/results_event.aspx?did=115400
- Course record (M): https://ultrasignup.com/results_event.aspx?did=49054
- Course record (F): https://ultrasignup.com/results_event.aspx?did=29872