The Whitewater River run begins at its headwaters in Sec. 21, T2S, R2W, Hm and flows for approximately 28 miles until it reaches its junction with the Mattole River in California. The ideal streamflow range for this run is between 100 and 500 cfs, although it can run higher during peak runoff periods. The class rating for this run ranges from Class II to Class IV, with the most challenging rapids found in the lower sections of the river.

The segment mileage for this run is broken down into three sections: the upper, middle, and lower. The upper section is approximately 10 miles long and features mostly Class II rapids with a few Class III sections. The middle section is around 7 miles long and is characterized by steep and narrow canyons with continuous Class III rapids. The lower section is the most challenging, with a mix of Class III and IV rapids, steep drops, and tight channels.

Specific rapids and obstacles to look out for on this run include Pinball, a Class III rapid in the middle section, and Triple Threat, a complex Class IV rapid in the lower section. There are no specific regulations to this area, but it is important to practice Leave No Trace principles and respect private property along the river.

Overall, the Whitewater River run offers a diverse range of rapids and challenges for intermediate to advanced kayakers and rafters. It is important to check water levels and bring appropriate gear and safety equipment before attempting this run.