Humboldt Bay Marathon

Held in August in Eureka, the Humboldt Bay Marathon offers a flat to gently rolling course that won't punish your legs with climbing, making it a solid choice if you're chasing a time or testing fitness without major elevation battles. The course stays low overall, ranging between sea level and just above 50 meters, so what you see is what you get in terms of effort. August in coastal Northern California means you should prepare for variable weather, potentially cool and damp conditions typical of the region. The race is road-based, so you'll be on pavement the whole way, which is good for your pace but worth noting if you prefer trail variety. Check the official race website closer to 2026 for start time, course specifics, and entry details, since logistics for a relatively smaller marathon can vary year to year.