The Whitewater River run from State Highway 21 to State Highway 7 in Texas is a popular destination for kayakers and rafters. The ideal streamflow range for the river is between 200 and 600 cfs, with peak flows occurring during the spring and early summer months. The river is rated as a Class II-III, making it suitable for intermediate-level paddlers.

The segment mileage from State Highway 21 to State Highway 7 is approximately 10 miles, with several rapids and obstacles along the way. Some of the notable rapids include Big Rock, Rollercoaster, and Rock Garden. The river also features several large boulders and drops that require skillful navigation.

To ensure safety and protect the environment, there are several regulations in place for the Whitewater River run. All paddlers must wear personal flotation devices and helmets, and commercial outfitters must be licensed by the state. Camping is allowed in designated areas only, and fires are prohibited. Additionally, all trash must be packed out, and visitors are encouraged to practice Leave No Trace principles.

Overall, the Whitewater River run is an exciting and challenging destination for paddlers in Texas. However, it is important to be mindful of regulations and safety guidelines to ensure a fun and safe experience on the river.