Healdsburg, CA, United States · Saturday, April 10, 2027

Fixed Distance 100K

Lake Sonoma 100K & 50K

194 days away
100 km Distance
3,200 m Climbing
9.8 Grit · Elite / extreme

What the course asks

Climbing rate 32 m / km Rolling. Moderate undulations. Requires consistent effort across varying grades.
Time limit 14 hours 8:24 min/km average. Comfortable. Room to walk the climbs and stop at aid. Tighter than 85% of 100K races. Measured against 214 races of the same distance. Cut-off calculator →
Field size ~218 Large. Rarely out of sight of another runner.

DUV results for the 2026 edition (50km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Results history

Year Race Finishers Men's winner Women's winner
2026 50km 218 Robbie Simpson · 03:39:39 Hannah Allgood · 04:19:36
2025 55km 102 Jacob Banta · 04:21:42 Joelle Vaught · 05:17:44
2024 55km 105 Matthew Seidel · 04:23:09 Pauline Loulier · 05:00:48
2023 55km 107 Benjamin Gallegos · 05:19:32 Zuzana Trnovcova · 05:20:25
2022 55km 58 Timothy Smith · 06:01:59 Alyssa Clark · 06:05:12

The field grew 114% between 2025 (102) and 2026 (218). 39% of the 2026 field were women.

DUV results for the 2026 edition (50km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

The Aid Station

Course-specific beta from the community

⛰️ terrain

This is a rolling course. Expect fast, runnable sections where rhythm is key.

By UltraHub Expert
👟 gear

With trail terrain, choose a shoe with moderate cushioning for optimal performance.

By UltraHub Expert
🥤 nutrition

For 100km+ efforts, prioritize real food at aid stations to prevent palate fatigue.

By UltraHub Expert

Gear for this race

Chosen for 100 km of trail with 3,200 m of ascent.

  • Trail Running Shoes 32 m of climb per kilometre — grip and rock protection before cushioning.
  • Race Nutrition Past 100 km the palate quits before the legs do — carry more than one flavour.
  • Hydration Vests Pole attachment and chest-strap stability on steep ground.
  • Trekking Poles 3,200 m of ascent to walk up.
  • Headlamps A 14 h limit puts you out there after dark.
All gear guides →

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