GUNNISON, Colo. (CBS4)- Three cyclists were rushed to the hospital after a crash of the Pro Cycling Challenge. They were rushed to the hospital in Gunnison.

It happened just after noon in Gunnison County, along the first part of Wednesday’s stage of the bike race. Today’s stage is said to be the most physically demanding, going up and over both Cottonwood and Independence Passes on the way to Aspen, both are more than 12,000 feet.

Race officials are estimating the race may draw more than 1 million spectators over the course of seven days. The race began on Aug. 22 and concludes Sunday in Denver with 70.9-mile Golden to Denver road race.

The race will cover more than 500 miles of Colorado terrain, including Aspen, Avon, Breckenridge, Colorado Springs, Denver, Gunnison, Salida and Steamboat Springs.