Fourmile Creek in Colorado offers a thrilling whitewater river run for kayakers and rafters. The ideal streamflow range for this creek is between 200-500 cfs (cubic feet per second) during the snowmelt season (April-June).

This creek is classified as Class III-IV, with sections of Class V rapids during high water, making it suitable for intermediate and advanced level boaters. The segment mileage for Fourmile Creek is approximately 7 miles, starting at Highway 285 and ending at the Arkansas River. The start of the run provides a few calm stretches, which are followed by challenging rapids such as the "Boneyard" and "Pinball."

One of the most significant obstacles on this creek is a series of low bridges, which require careful navigation. Additionally, the creek runs through private property, so boaters are required to stay on the water and avoid trespassing. The Arkansas Headwaters Recreation Area manages this section of the creek and enforces regulations such as wearing a PFD, respecting private property, and avoiding littering.

Overall, Fourmile Creek offers an exciting river run for experienced whitewater enthusiasts, with a range of challenging rapids and specific regulations to ensure the safety and preservation of the area.