The Whitewater River Run on the San Joaquin River is a popular class III-IV+ whitewater run in California. The ideal streamflow range for this run is between 600-1000 cfs, which typically occurs during the spring and early summer. The segment mileage of this run is approximately 15 miles long, starting at the Headwaters at Thousand Island Lake and ending at Agnew Meadows.

The run includes several challenging rapids, such as "Devil's Postpile," "Rainbow Falls," and "Hole in the Wall," each with its unique obstacles and challenges. Paddlers must navigate through tight boulder gardens, steep drops, and strong currents, requiring advanced technical skills and experience.

In terms of regulations, paddlers must obtain a permit to access this area, as it is located within the Ansel Adams Wilderness. Additionally, there are strict guidelines for camping and fire use to protect the fragile ecosystem of the region.

Overall, the Whitewater River Run on the San Joaquin River offers a challenging and exhilarating experience for experienced paddlers. It is important to note that this run is not suitable for beginners or those without advanced technical skills. It is essential to check current streamflow levels and weather conditions before embarking on this adventure to ensure safety and enjoyment.