The Whitewater River Run begins at the headwaters and includes all tributaries to the confluence with Boulder Creek in Washington State. The ideal streamflow range for this stretch of river is between 200-500 cfs. Its class rating ranges from Class II to Class IV, with some sections being more technical than others. The segment mileage of the Whitewater River Run is approximately 10 miles long.

One of the main rapids on this run is called "Pinball," which is a Class IV rapid that requires technical maneuvering through a series of boulders. Another notable rapid is "S-Turn," which is a Class III rapid that requires precise boat control to navigate through a tight channel of rocks.

There are specific regulations in place for this area, including a permit system for commercial outfitters, as well as restrictions on camping and fires along the riverbank. It is also important to note that this area is located on the traditional lands of the Yakama Nation and visitors are encouraged to respect their sovereignty and cultural heritage.