The Snake River - 4.01 is a popular whitewater run located in the state of Washington. The ideal streamflow range for this river is between 1,500 and 4,500 cfs. The class rating for this segment of the Snake River is Class III-IV, making it suitable for experienced kayakers and rafters.

The segment mileage for the Snake River - 4.01 run is approximately 9 miles. This section of the river features several challenging rapids and obstacles, including the Big Kahuna, the Lower Granite Rapid, and the Pinball Rapid. These rapids offer a thrilling ride for experienced whitewater enthusiasts.

There are several regulations that apply to the Snake River - 4.01 run. Rafters and kayakers must wear life jackets and helmets at all times while on the river. Additionally, motorized boats are not permitted on this segment of the river, and all vessels must carry a throwable flotation device.

Overall, the Snake River - 4.01 is a challenging whitewater run that offers experienced kayakers and rafters an exciting adventure. With its ideal streamflow range, class rating, and specific rapids and obstacles, it's no surprise that this run is a popular destination for thrill-seekers.