The Whitewater River run in Lassen National Park, California, stretches from the park boundary to just below the Highway 36 crossing. This segment spans approximately 10.8 miles and is rated as a class III-IV rapid with an ideal streamflow range of 300-2000 cfs. The river's rapids are mostly technical and require experienced paddlers to navigate through them safely. Some of the river's rapids include The Chute, The Devil's Kitchen, and the Bouncing Rock.

There are several regulations in place to ensure the safety of all visitors to the area. These regulations include wearing personal floatation devices and helmets at all times while on the river. The use of alcohol and drugs is prohibited, and visitors are urged to respect the environment by leaving no trace of their visit.

It is essential to note that access to the Whitewater River run may be restricted during certain times of the year due to weather conditions, and visitors should check with park authorities before planning their trip. With its diverse rapids and beautiful scenery, the Whitewater River run is a must-visit for experienced paddlers looking for a challenging adventure.