Expected April 2028
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The Lake Sonoma 100K & 50K is held at Lake Sonoma near Healdsburg in Sonoma County, California, and the 2027 edition is the seventh running of the event. The 50K is almost entirely off road, with roughly 86 percent single-track trail, 9 percent dirt road and a small amount of pavement, and it climbs and descends about 3,200 metres in total. Runners start at 7:30 am on 10 April 2027 and have 14 hours to finish, and the field is limited to 300 starters. The race has drawn a strong trail field in recent years, with winning 50K times around 3 hours 40 for men and 4 hours 20 for women. It sits in the DUV ultra marathon calendar as a non-ranked event with no IAU label.
Single-track trails around Lake Sonoma
Sonoma County wine country scenery
86% single-track trail surface
Long-running California trail classic
Start / Finish
Lake Sonoma, Healdsburg, California, USA
Lake Sonoma, Healdsburg, California, USA
Terrain
Route
Race Day
Other questions
It is a trail running event held at Lake Sonoma near Healdsburg in Sonoma County, California. The 2027 edition is the seventh running of the race, it offers a 100K and a 50K, and the shorter distance starts at 7:30 am on 10 April 2027.
Skip Brand is the race director and is the listed contact for the event. He can be reached by email at [email protected].
The event page lists no qualifying standard and no lottery. Places are sold through UltraSignup until the 300 runner field is full.
There are two races on race weekend, a 50K and a 100K, so runners can choose between a shorter and a much longer day on the trails around the lake.
The 50K attracts a strong trail field. Recent editions have been won in around 3 hours 40 by the leading man and around 4 hours 20 by the leading woman, and the 2026 race alone had 132 male and 86 female finishers.
Entry fee
Registration isn't open yet. We'll show pricing when the organiser confirms.Healdsburg, USA
Expected April 2028
Provisional date, around Apr 8Are you the organiser of 7th Lake Sonoma 100K & 50K?
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