The Middle Fork Bull River run is a popular whitewater destination in Idaho, spanning from Section 9, T28N, R33W to the proposed addition to Cabinet Mtns Wilderness in Section 12, T28N, R33W. The ideal streamflow range for this segment is between 500-1500 cfs. The class rating for this run is Class III-IV, with a total segment mileage of 10.5 miles.

The river features several challenging rapids and obstacles, including "The Maze," "Merry-Go-Round," and "Jaws." "The Maze" is a complex section of the river with multiple channels, requiring precise navigation. "Merry-Go-Round" is a technical rapid with a tight entrance and steep drop, while "Jaws" features a large boulder that creates a powerful hydraulic.

In terms of regulations, the Middle Fork Bull River run is managed by the Kootenai National Forest. Boaters are required to obtain a permit from the Forest Service, and group size is limited to 15 people. Additionally, boaters are required to pack out all trash and follow Leave No Trace principles.

Overall, the Middle Fork Bull River run offers challenging rapids and beautiful scenery, making it a popular destination for experienced whitewater enthusiasts. It is important to research current streamflow conditions and comply with regulations to ensure a safe and enjoyable experience.