A quick look at the Dirty Kanza 200, an extreme bike ride

The Dirty Kanza 200 is a self-supported, 200-mile bike race through the rolling Flint Hills of southeastern Kansas. It is part of a boom of extreme distance events that are allowing athletes to take their mental and physical endurance to the very limits. Here is what you need to know about the race:

THE RULES: Riders can receive no help aside from a couple of checkpoints, where their team can resupply them. Otherwise, they must carry everything - food, equipment, spare tires.

THE ROUTE: The ride begins outside the historic Granada Theater in downtown Emporia, and ends there 12 to 24 hours later, depending on how long the stragglers take to finish. It takes riders on gravel through one of the world's last remaining tallgrass prairies.

THE FIELD: What once consisted of just 34 riders has grown to nearly 2,000, with nearly a thousand of them riding the full route. Others will ride an abbreviated 100-mile event, and others a 50- and 20-mile option. There are some professional riders, such as endurance specialist Rebecca Rusch, but most of the field is recreational cyclists testing their limits.

THE PERILS: Fatigue, for starters, both physical and mental. The weather is another: The ride goes on rain or shine, whether there are triple-digit temps or it's barely above freezing. While it has never been an issue, riders must be wary of poisonous snakes and other animals.

THE SPOILS: Prize money? Not quite. The winners in each class get custom belt buckles.