The Whitewater River Run Headwaters to Confluence with Little Boulder Creek is a popular river run in Idaho with a class rating of II-III. The ideal streamflow range for this segment is between 300-1500 cfs, with the best time to go being in the late spring to early summer. The segment mileage is approximately 6 miles, with some notable rapids and obstacles including "S-turn," "Little Falls," and "Pinball."

As for regulations, the Idaho Department of Fish and Game requires a fishing license for anyone who wants to fish in the river. Additionally, all boaters are required to wear a personal flotation device while on the water. It is also important to note that the river run passes through private property in some areas, so it is necessary to respect landowners' rights and abstain from trespassing.

Overall, the Whitewater River Run Headwaters to Confluence with Little Boulder Creek offers an exciting and challenging adventure for intermediate-level boaters. With its scenic views and thrilling rapids, it is no surprise that this run is a favorite among locals and tourists alike.