The whitewater river run at Atastra Creek in California has an ideal streamflow range of 200-500 cfs. The segment mileage of this run is approximately 4.5 miles, making it a relatively short but intense trip. The class rating for this run ranges from Class III to Class V, providing a challenging experience for experienced paddlers.

The river rapids and obstacles on this run are numerous, with notable features such as "The Slot" and "The Squeeze." These features provide exciting challenges for paddlers and require precise navigation skills. One of the most significant obstacles on this run is the "Undercut Rock," which requires careful attention to avoid getting stuck or flipped.

There are specific regulations in place for the Atastra Creek run, including a permit requirement from the Bureau of Land Management. Paddlers must also adhere to Leave No Trace principles, as this area is a sensitive ecosystem. Additionally, paddlers must be aware of the potential for flash flooding in the area and should avoid the creek during times of heavy rainfall.

Overall, the Atastra Creek whitewater river run provides a thrilling experience for experienced paddlers in a beautiful natural setting. However, it is crucial to follow regulations and take necessary precautions to ensure a safe and enjoyable trip.