The Main Branch of the Whitewater River in Illinois is a popular destination for kayaking and canoeing enthusiasts. The ideal streamflow range for this river run is between 300 and 800 cubic feet per second (cfs). The river is classified as a Class II-III, which means it has moderate to difficult rapids with some obstacles and waves that require maneuvering.

The segment mileage for the Main Branch river run is approximately 6.5 miles, beginning at the Headwaters and ending at Forest Road 2174. Along the way, paddlers will encounter several specific river rapids and obstacles, including the Blackhawk Rapids and the Tinker's Dam Rapid. The river also has several large rocks and submerged logs that can pose a hazard, especially during periods of high water.

There are specific regulations that paddlers must follow while on the Main Branch river run. The river is part of the Whitewater River State Fish and Wildlife Area, and all Illinois fishing and boating regulations apply. Paddlers must wear a personal flotation device at all times, and alcohol is prohibited on the river. Additionally, all camping on the riverbank is prohibited.

Overall, the Main Branch of the Whitewater River in Illinois offers a challenging and exciting river run for experienced kayakers and canoeists. However, it is important to check the streamflow range and be aware of specific regulations before embarking on this adventure.