Where: Santa Rosa, CA
When: October 4
How far: 32, 65, or 103 miles
Price: from $80, levisgranfondo.com
Why it's a must: Levi Leipeheimer, a three-time Tour of California champ and 2008 Olympic bronze medalist, doesn't just lend his name to this challenge – he participates, too, and usually with his well-known pro and celeb friends, including avid cyclist Patrick Dempsey. "Sonoma County is arguably the best riding terrain in the country. On the course, you experience several micro-climates and distinctly different environments, from canopied forests to wide-open ridges overlooking the Pacific Ocean," says a senior-level CTS coach Charlie Livermore. Another highlight is Santa Rosa itself. "The community really gets behind this event. Volunteers come out in droves to support the 7,500 riders every year. Afterward, you see them all again at a great post-event party to celebrate your accomplishment," he adds.