The Whitewater River Run in Washington state is a popular destination for whitewater enthusiasts. The river runs for approximately 10 miles from its headwaters to its confluence with the North Fork Bogachiel River. The ideal streamflow range for the Whitewater River is between 800 and 3,000 cubic feet per second (cfs), with peak flows occurring during the spring and early summer months. The river is rated as a Class III to IV, with challenging rapids such as Boulder Drop, the Narrows, and Jaws.

The segment mileage of the Whitewater River Run can vary depending on the put-in and take-out points, but the most common run is around 8 miles. The river features several technical rapids and obstacles, including boulder gardens, steep drops, and tight chutes. Some of the rapids require precise maneuvers and are best suited for experienced paddlers.

As for regulations, the Whitewater River Run falls within the Olympic National Park and is subject to specific rules and guidelines. All paddlers must obtain a backcountry permit and follow Leave No Trace principles. Additionally, motorized boats are not allowed on the river, and the use of drones is prohibited.

In summary, the Whitewater River Run is a challenging and exciting whitewater destination with a Class III to IV rating. The ideal streamflow range is between 800 and 3,000 cfs, and the run covers approximately 8 miles. Precise maneuvers are required to navigate the challenging rapids, and paddlers must follow specific regulations set by the Olympic National Park.