Levi's GranFondo — The Growler
The Growler is Levi's GranFondo's elite road race: 137.5 miles, 13,867ft through Sonoma County — widely called America's hardest gran fondo route.
The vibe
America's hardest gran fondo, no debate
137.5 miles. 13,867 feet of climbing. The Growler is Levi’s GranFondo’s elite road race, and it earns its reputation — a route that threads through old-growth redwood forests, drops to Pacific coast views, and accumulates elevation without mercy until you cross the line back in Windsor. This is where riders who’ve “done the Gran” come back to prove something else entirely.
The elite field rolls out first at 7:15 AM with separate categories for men, women, and juniors. All Growler racers are required to attend (or watch) a live racer meeting the evening before — this is a competitive event with real racing, not just a long ride with timing chips. The Skipstone estate, a 200-acre certified-organic vineyard right along the route, is one of those surreal California moments that reminds you exactly where you are.
If you’re targeting this one, build your base around consecutive long days with serious vertical. The Growler is a genuine athletic statement, but the event wraps it in exceptional infrastructure — closed roads, multiple aid stations, full marshaling — so the only variable left is you.