The Whitewater River Run from the confluence of East and West Forks of Foss River to confluence with Tye River in the state of Washington is a popular destination for whitewater enthusiasts. The ideal streamflow range for this segment is between 600-1500 cfs, with the best time to visit being in the spring and early summer months. The segment is rated as Class III-IV rapids, making it suitable for experienced paddlers or those with a guide.

The segment covers a distance of approximately 5.5 miles and features a number of notable rapids and obstacles, including the "Zig Zag" and "Toilet Bowl" rapids. These rapids are characterized by large waves, steep drops, and strong currents.

In terms of regulations, boaters are required to follow all state and federal laws, including wearing a personal flotation device at all times and carrying proper safety equipment. The area is also subject to seasonal closures and restrictions, so it is important to check with local authorities before planning a trip.

Overall, the Whitewater River Run from the confluence of East and West Forks of Foss River to confluence with Tye River is a challenging and rewarding experience for those with the necessary skills and equipment. It is important to approach this segment with caution and respect for its natural beauty and potential dangers.