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Lake Sonoma 50

Quick facts

Distance Ultra marathon

About Lake Sonoma 50

Lake Sonoma was created in 1983 by the construction of the Warm Springs Dam. At capacity, the lake covers 2,700 acres and offers 50 miles of coastline. Managed by the US Army Corps of Engineers, over 17,000 acres of lake and surrounding recreation area offer a wide variety of activities, including hiking, mountain bike and horseback riding, boating, camping, fishing and hunting. More than 40 miles of hiking, biking and equestrian trails meander around the two main arms of the lake, taking in rolling coastal foothills of redwood groves, oak woodlands, mixed forests, grassy slopes and steep hills. The lake features some of the best bass fishing in the state, along with steelhead, trout, catfish and perch. Lake Sonoma has 109 primitive campsites and two group-use campsites that are accessible by boat and/or trail only. One drive-in campground is also available. Lake Sonoma, also hosts the annual Lake Sonoma 50.

Lake Sonoma 50 is a 50-mile ultra marathon race held near Healdsburg, California. The course circumnavigates the Warm Springs arm of Lake Sonoma on hiking trails. It takes place annually on the second Saturday in April. The race was first run in 2008. In recent years it has become one of the most highly competitive ultra marathons in the United States.


Lake Sonoma 50

  • 80.467km



Best Western Dry Creek Inn, Super 8 Cloverdale, America’s Best Value Inn Healdsburg,

After Race Services

There will be porta-potties and we will provide a large tent for shelter.

Aid Stations

Aid stations will be stocked with the normal ultra fare, and will have GU Energy Gels, GU Energy Chews and GU Roctane Energy Drink.

Award Medals

The top two men and women finishers will each earn a spot at the Western States 100. The first U.S. male and first U.S. female from at Lake Sonoma will earn a spot on the team participating in the IAU Trail World Championship.

Equipment Storage

Drop bags will be transported to the No Name Flat aid station at mile 25.2 and to Warm Springs Creek, which you will pass at mile 11.6 and 38.0.

Maximum Time

14 hrs


Parking available at South Lake Trailhead parking lot


Finish line food will feature gourmet tamales (both chicken and veggie) by renowned chef Mateo Granados of Mateo’s Cocina Latina restaurant, and delicious sandwiches from the World Famous Hamburger Ranch and Pasta Farm.


South Lake Trailhead





Soda Springs Reserve

Healdsburg Ridge

Foothill Regional Park

Milt Brandt Visitor Center

Congressman Don Clausen Fish Hatchery

Warm Springs Recreation Area


The course is an out-and-back circumnavigation of the Warm Springs Arm of Lake Sonoma. It is 86% single-track trail and 9% dirt fire roads, with the first 2.4 miles on pavement. The trail is relentlessly rolling with three significant climbs. There is about 10,500 feet of elevation gain and an equal amount of loss over the 50 miles. Trail quality is generally good; there are very few rocks and almost no roots. However, much of the trail is seldom used and so you can expect a lot of leaves and sticks on the trail. There are twelve creek crossings and it is likely that your feet will get wet in most, if not all of them.

The race information has been found on the official website of the event or through publicly available sources. Always refer to the official website the latest race information. Please let us know if any data is wrong or missing, by emailing us.