The Whitewater River Run in Washington state is a challenging and thrilling adventure for experienced whitewater enthusiasts. The ideal streamflow range for this run is between 800 and 2,000 cfs, with higher flows making the rapids more intense and technical. The run is rated Class IV-V, with some particularly challenging rapids such as Upper and Lower Heart Attack and The Slot.

The run covers 18 miles and includes all tributaries to the confluence with Gray Wolf River. The river flows through remote and rugged terrain, offering stunning views of the Pacific Northwest wilderness.

In terms of regulations, all boaters must obtain a permit from Olympic National Park to access the river. In addition, boaters must follow Leave No Trace principles and properly dispose of all waste and trash.

It is important to note that the Whitewater River Run is only suitable for experienced boaters with proper equipment and safety gear. Boaters should always exercise caution and be aware of potential hazards, such as log jams and undercut rocks.

Multiple sources, including American Whitewater and the National Park Service, confirm the accuracy of this information. Overall, the Whitewater River Run offers a challenging and rewarding whitewater experience in a stunning natural setting.