The Whitewater River run from Highway 4 to Salt Springs Reservoir in California is a popular destination for kayaking and rafting enthusiasts. The ideal streamflow range for this section of the river is between 300 and 800 cubic feet per second (cfs), which can be easily checked on the United States Geological Survey (USGS) website.

This section of the river is rated as Class III (intermediate) with some challenging Class IV (advanced) rapids. The total segment mileage is around 8 miles, with several rapids and obstacles along the way, such as "Satan's Cesspool," "The Elevator," and "Deadman's Drop."

To ensure the safety of all visitors, there are specific regulations to the area. The use of personal flotation devices (PFDs) is mandatory for all individuals on the river. Additionally, fires, littering, and camping outside of designated areas are strictly prohibited.

It is highly recommended to go with a licensed outfitter or experienced guide for this river run, as the rapids and obstacles can be challenging for even the most experienced kayakers and rafters. Overall, the Whitewater River run from Highway 4 to Salt Springs Reservoir is an exciting and scenic adventure for those looking for a thrilling whitewater experience in California.