Lake Sonoma 100K, 50K & TS Half

Spring into action at Lake Sonoma for an unforgettable trail running experience on April 10, 2027! The adidas Lake Sonoma race series offers three distinct challenges: the grueling 100K ultra course, the rugged 50K event, and a women-only half marathon. Each race is set against the backdrop of rolling hills, oak-dotted ridgelines, and stunning views over serene Lake Sonoma.
The 100K route begins with an early morning ascent up Pritchett Peak, where runners are greeted by sunrise at the summit. Descending to the Lake Sonoma Visitor Center marks a transition into more technical trail running through madrone groves, singletrack paths, and scenic overlooks of the lake. With 13 aid stations along its remote course—eight full service and five water-only—the event demands endurance and mental fortitude. Runners must navigate long stretches between aid points, carrying enough supplies for up to six miles at a time.
The 50K kicks off from the Visitor Center with initial paved sections giving way to singletrack trails that wind through forested terrain. The course features punchy ascents and descents before flattening out along lakefront paths toward the finish line. Six aid stations, including two water-only stops at South Lake and Wulfow, provide essential hydration and nutrition.
For women seeking a unique challenge in an encouraging community atmosphere, the Trail Sisters Half Marathon offers 13 miles of rolling terrain with breathtaking views over Lake Sonoma. Aid stations are placed every three to four miles along this scenic route, ensuring runners have access to necessary supplies throughout their journey. Shuttle transportation is available from the finish back to the start.
All races feature live timing by UltraLive.net and EMT services provided by NoSoCo Fire Department. Runners should be prepared with headlamps for late afternoon sections of the 100K course after 3:30 PM, ensuring safety during longer daylight hours in springtime California.
Upon crossing the finish line, participants are greeted not just with accolades but also custom gifts such as wine bottles or non-alcoholic alternatives. A warm and supportive atmosphere pervades throughout the event weekend, blending rugged adventure spirit with laid-back hospitality typical of Sonoma's renowned wineries and vineyards.
Whether you're pushing your limits on a challenging ultra course or enjoying camaraderie in a half marathon designed specifically for women, Lake Sonoma offers an unmatched blend of natural beauty and competitive excitement. Join us this April to experience the magic of trail running amidst one of California’s most picturesque settings!