The Whitewater River, located in the state of Washington, is a popular destination for kayaking and rafting enthusiasts. The ideal streamflow range for this river is between 500 and 1,000 cubic feet per second (cfs), with the best time for paddling being in the spring and early summer months. The segment mileage of the run is approximately 1.4 miles, starting upstream from the confluence with the Elwha River and ending at the confluence.

The class rating for the Whitewater River run is Class III, with some Class IV rapids and obstacles. The river features several challenging rapids, including the "Whiplash" and "S-Turn" rapids, which require precise maneuvering and technical skill. There are also several large boulders and drops to navigate, which can be particularly challenging during periods of high water flow.

In terms of regulations, kayakers and rafters are required to have a valid Washington State Discover Pass to access the river. Additionally, all paddlers are required to wear proper safety equipment, including a personal flotation device and helmet. It is also recommended that paddlers be experienced in whitewater kayaking or rafting before attempting this run.

Overall, the Whitewater River run offers a challenging and rewarding experience for experienced paddlers seeking an adrenaline-filled adventure. However, it is important to always prioritize safety and follow all regulations and guidelines when navigating this river.