The Whitewater River Run from Headwaters to Eastern Boundary of Olympic National Park in Washington State is a thrilling adventure for experienced kayakers and rafters. The ideal streamflow range for this run is between 700 and 1,200 cfs. The river has a class rating of III to IV, meaning it is moderately difficult with rapids that require technical skills and maneuvering. The segment mileage is approximately 12 miles, with a descent of over 1,000 feet.

Specific river rapids and obstacles to watch out for include Devil's Punchbowl, a Class IV rapid with a steep drop, and a boulder garden that requires precise navigation. The Cutthroat Creek waterfall is a scenic highlight and can be portaged if necessary. There are also several other Class III rapids that provide exciting challenges.

To ensure safety, specific regulations are in place for the area. All participants must wear appropriate safety gear, including helmets and personal flotation devices. The Olympic National Park also requires a permit for all river trips, which can be obtained through the park's website. It is recommended that participants have prior experience in whitewater kayaking or rafting and are familiar with the specific challenges of this run. It is also important to check the current streamflow levels and weather conditions before embarking on the journey.