The Whitewater River Run from Yellowstone National Park to Targhee National Forest Boundary in Idaho is a thrilling adventure for experienced kayakers and rafters. The ideal streamflow range for this run is between 800-1500 cfs, with the peak season being late May to early July.

This run is classified as Class III-IV rapids, meaning intermediate to advanced paddling skills are required. The segment mileage is approximately 18 miles, with a total run time of 4-6 hours.

Some of the specific river rapids and obstacles to watch out for include the Colter Falls, which is a Class IV rapid with a large boulder in the center of the channel. The Tumbleweed Rapid, a Class III rapid with a narrow channel and large rocks, is also a challenge.

There are specific regulations for this area, including a permit requirement for commercial outfitters and a strict "pack it in, pack it out" policy for all visitors. Additionally, there are restrictions on camping and campfires in certain areas.

Overall, the Whitewater River Run is an exhilarating experience that requires proper planning, equipment, and safety precautions.