Races

TERREX Lake Sonoma 100k

CaliforniaApril

Lake Sonoma, California. TERREX hundred k. Ten thousand five hundred feet. Wine country heat.

62 mi+415 ft-418 ft19 hours810 ft to 864 fttech 5/10Checkpoints per race bookLake Sonomawine countryWSER qualifierApril
Distance62 mi
Gain+415 ft
Loss-418 ft
Altitude810 ft to 864 ft
Technicality5/10
Air45°F to 90°F
Gradient profileOfficial race GPX
  • Start820 ft
  • High864 ft
  • Low810 ft
  • Finish817 ft

Field, 2026 · 6-year samplescraped

Starters140
Finish rate69%
Median15:50
Sub-2497

Geometryderived

Steepest drop46 ft-0.4% over 2.2 mi
Night miles16 misunset near 19:00 local

Course records

Men8:36:09Ryan Sullivan2026 scraped
Women10:13:24Fiona Pascall2026 scraped

The cruxLake Sonoma dam climb in April heat (near mile 40)

Course DNA

The Course

TERREX Lake Sonoma 100k runs 100 km through California. +415 ft gain and -418 ft loss. Surfaces skew 80% trail / 20% dirt road. Lake Sonoma dam climb in April heat. High point near 864 ft. Low near 810 ft. April temps run 45°F to 90°F. The course rewards patience early and punishes rushed descents after mile 31.

The Work

Train for 415 feet of climbing across 100 km. Back-to-back long runs on trail. Practice power-hiking grades above 15 percent. 19 hours total means limited margin: rehearse fueling every 45 to 60 minutes and downhill eccentric work weekly. Technicality 5/10. Build a block that simulates the crux near mile 40.

Kit

April in California: plan for 45°F to 90°F. Mandatory shell if rain is in forecast. Headlamp with spare batteries if 19 hours pushes past dark. Poles help on sustained climbs above mile 16. Vest capacity for 2 liters minimum. Shoes matched to 80% trail: lugs for mud, rock plate if the course turns technical after mile 31.

Race Day

Hold effort through mile 16. The field often splits on the first big climb after mile 31. Lake Sonoma dam climb in April heat near mile 40 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 21 miles of fatigue management. Finish with reserve for the last descent.

Results

TERREX Lake Sonoma 100k finish lines.

TERREX Lake Sonoma 100k

100KHealdsburg

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Train for TERREX Lake Sonoma 100k

Course-specific plan, fuel segments, gear kit, and race morning for TERREX Lake Sonoma 100k.

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TERREX Lake Sonoma 100k

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