Sonoma Fall Classic (Lake Sonoma 50)

The Sonoma Fall Classic runs October 17–18, 2026, around Lake Sonoma near Geyserville, California. Put on by Aravaipa Running with Healdsburg Running Company and race founder Tropical John Medinger, it is now the home of the Lake Sonoma 50, which left its traditional April date this year. The 50-miler (51.5 miles, about 10,600 feet of gain, 16-hour limit) returns to its original course and starts at The Ranch at Lake Sonoma at 6:30 a.m.

Every race starts on Saturday, October 17, and finishes at the Lake Sonoma Recreation Area: the 100-mile Sufferfest (100.5 miles, about 25,000 feet of gain, 36 hours) at 5 a.m., the marathon (26.8 miles, 5,900 feet) at 8 a.m., the half (12 miles, 2,260 feet) at 10 a.m. from Liberty Glen, plus 4-person relays over 100 and 50 miles. Bib pickup is October 15–16 at Healdsburg Running Company, or at your start on race morning. Registration for 2026 closed on October 12. The April race carries on as the Lake Sonoma 100K, 50K & Trail Sisters Half.