2. Breck Epic
Source: Iconosquare
Breckenridge, Colorado–This August race is five stages of about 50 miles each through very mountainous terrain. It’s all mountain biking, and you are required to wear a helmet, and not be a “jerk” to other riders according to the instructions on the website. It takes about 6 days to complete, and is a little less serious than some of the other extreme races. It has a party vibe to the overall feel of the race, so you can enjoy it with some of your other endurance racing pals.