If you are interested in the USA Pro Cycling Challenge, you probably know the most pertinent information: 128 of the world's best cyclists, including the top three Tour de France finishers, will race over 600 miles and reach elevations that few races, if any, have reached before. The competition, which started today in Colorado Springs, is billed as a showcase of Colorado as well as the largest spectator event in the state's history. Here are five things to know about the race that you might not have heard. 5. The prologue is huge: Both in terms of length and importance, today's prologue in Colorado Springs, is extremely important. Racers will start at the Garden of the Gods and pedal into Colorado Springs. The prologue is a time trial over five miles -- a normal prologue is about two or three -- and a rare descent in elevation during this race.

"It's an unusually long time trial and you will hear the riders say they think a lot of the race will actually be won in the prologue," says race spokeswoman Stacie Langue. "The reason being they get to try to capture as much time as they can in the prologue to bank for later in the race when they're doing the climbs."

The riders will actual lose 219 feet in elevation during the prologue. Tomorrow, cyclists will gain over 8,000 feet riding from Salida to Crested Butte. 4. You can watch for free: Not only can you attend the event for without charge and watch each day on Versus -- and Sunday on NBC -- but you can get online and watch the race through the Shack Tracker. And the Tracker is not just a simple live feed. "Unlike TV, it's interesting because it also tracks biometrics of the riders, in terms of their heart rate, power output, the elevation they're riding at," says Langue. "You kind of have an insider's view to what is going on with the riders as you're watching them." will gain over 8,000 feet riding from Salida to Crested Butte. 3. The Vail stage is a thowback: The Vail time trial is a ten-mile, uphill battle, but it also gives a tip of the cap to an iconic Colorado bike race that took place in the 1980s. "What is unique about Vail is that time trial is pretty much re-created from the Coors Classic," says Langue. "That course is almost exact to what the Coors course was way back when. It's historical that we've re-created a lot of the Coors Classic and we're going to have a lot of the riders from the Coors Classic there for the race." 2. The Denver stage is new school: At most of the locations, spectators will be camped out on the side of the course and will have a few minutes of exhilaration as the pack zooms past them. But when the racers close in on the finish in downtown Denver Sunday, they will travel through a five-mile loop six times.

"Where you're standing to watch the race downtown at Civic Center, you get to see them come by not just once, but six times," says Langue. "I think that's a really unique experience and one that not many people have been talking about."

Once all the racers have crossed the finish line, a large party featuring live music from the Flobots and a beer garden will ensue. 1. Local boy done good: Tom Danielson has had a hell of a year already, and for the Boulder resident, a win here would push it over the top. He finished ninth overall in the Tour de France, making him the highest placing American. His team, Garmin-Cervelo, won the Tour de France team title. He also finished third in the Tour of California.

The Fort Lewis College graduate is many people's favorite to win this race and it would be a storybook ending for this Colorado tale.

More from our Sports archive: "Lance Armstrong: Has he retired from involvement in USA Pro Cycling Challenge?"

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