The Whitewater River begins its journey in the San Bernardino Mountains, specifically in Sec. 19, T3S, R1W, Hm, and flows for approximately 30 miles until it empties into the Pacific Ocean in Southern California. The ideal streamflow range for the river is between 200-400 cfs, which makes it perfect for rafting and kayaking. The river is rated as a class III-IV, which means that it features moderate to difficult rapids with waves up to 4 feet and some obstacles that should be approached with caution.

The segment mileage of the Whitewater River is divided into different sections, each with its own set of rapids and obstacles. The first section, from the headwaters to Palm Springs, is 10 miles long and features exciting rapids such as "The Chute" and "Pinball." The second section, from Palm Springs to the Mission Creek Preserve, is 8 miles long and includes the famous "Cathedral Canyon" and "The Maze" rapids. The third and final section, from the Mission Creek Preserve to the Pacific Ocean, is 12 miles long and features the most challenging rapids, such as "Mother's Rapid" and "The Corkscrew."

To protect the natural environment and preserve the safety of visitors, the Whitewater River is subject to specific regulations. For example, visitors are required to wear appropriate safety gear, including helmets and life jackets, while on the river. Additionally, visitors are not allowed to litter, disturb wildlife, or damage vegetation in the surrounding area. Overall, the Whitewater River is a thrilling and exciting destination for outdoor enthusiasts looking for a challenging and beautiful river run in Southern California.