The Whitewater River Run Wilderness Boundary to South Fork Sun River is a popular destination for whitewater rafting enthusiasts. The ideal streamflow range for this section of the river is between 800 and 1500 cubic feet per second (cfs), with higher flows in the spring due to snowmelt. The segment mileage is approximately 12 miles with a class rating of III-IV.

There are several notable rapids and obstacles along this section of the river, including Cut Bank Rapid, which has a large rock in the middle of the channel, and a steep drop at the bottom. Another challenging rapid is Deadman's Eddy, which has a sharp turn followed by a narrow chute. The river also features several large boulders and narrow channels that require careful navigation.

Visitors to this area should be aware of specific regulations, including the requirement to obtain a permit from the U.S. Forest Service before launching on the river. Additionally, visitors should follow Leave No Trace principles, including packing out all trash and minimizing impact on the surrounding wilderness area.

Overall, the Whitewater River Run Wilderness Boundary to South Fork Sun River offers a thrilling and challenging whitewater experience for experienced rafters, with specific regulations in place to protect the natural environment.