The Whitewater River run in California begins at its headwaters in Section 6, T4S, R1E, Hm and flows until it reaches the junction with the main stem in Section 9 T4S, R1E, Hm. The ideal streamflow range for this river is between 500 and 1,000 cubic feet per second (cfs). The class rating for this river run ranges from III-IV, making it a moderately challenging run. The segment mileage for the Whitewater River run is approximately 16 miles.

While traveling down this river, rafters can expect to encounter several rapids and obstacles. Some of the specific rapids and obstacles include the Fisherman's Drop, where the river drops sharply over a small waterfall, and the Devil's Toilet Bowl, which is a large hydraulics feature that requires careful navigation. The river also features several narrow chutes and boulder gardens that require precise maneuvering skills.

There are specific regulations that rafters should be aware of when traveling down the Whitewater River. For instance, the use of personal flotation devices (PFDs) is mandatory for all rafters. Additionally, motorized vessels are not allowed on this river, and all boats must be inspected for invasive species before entering the water.

In conclusion, the Whitewater River run in California is a challenging but rewarding river run that offers a variety of rapids and obstacles for experienced rafters. With an ideal streamflow range of 500-1,000 cfs, a class rating of III-IV, and a segment mileage of 16 miles, this river run is sure to provide an exciting and memorable adventure.