The Cross Mountain Gorge River Run in Colorado provides an exhilarating experience for experienced rafters. The river run is classified as Class IV, and it features several challenging obstacles such as House of Rocks, Seldom Scene, and Hell's Half Mile. The best time to float this section of water is between May and August when the water levels are between 1,500 and 3,000 cfs. However, caution is advised as water levels can rise quickly, creating hazardous conditions. Overall, the Cross Mountain Gorge River Run is an exciting challenge for experienced rafters seeking to test their skills.