On June 15th, 24 cyclists lined up their mountain bikes on the Montana/Canadian border for the start of the 4th Annual Great Divide Race. Their goal: Mexico, as fast as possible. Their course is the Great Divide Mountain Bike Route, a 2,490 mile path criss-crossing the Continental Divide 28 times and climbing 200,000 feet, a course which they ride totally unsupported, carrying all of their own food and water, making their own repairs, and setting up their own camps along the way.

The record for the race, an incredible 16 days, 57 minutes set by race organizer Mike Curiak, is expected to fall this year. In fact, the current leader, Jay Petervary, a carpenter from Jackson, Wyoming, was in Southern Colorado yesterday, riding from Canada to Colorado in a week, a pace that would easily break the record if it can be sustained.

Photographer and cyclist Aaron Teasdale was on hand for the race start and has put together a gallery of images at Adventure Cycling. You can also see images of the beautiful route from previous races on the blog of competitor Matthern Lee. And if you want to keep tabs on the race in progress, you’ll find text and audio updates from this year’s competitors at www.greatdividerace.com.