The Rio Grande River Segment B is a popular destination for whitewater rafting in the state of Colorado. It is located in the San Juan Mountains and offers a challenging and exciting experience for experienced rafters. The ideal streamflow range for this segment is between 500 and 1,200 cfs, which typically occurs during the months of May and June.

The segment is rated as a Class III-IV river, which means it has moderate to difficult rapids that require precise boat handling. The segment covers a distance of approximately 10 miles, and the run takes around 2-3 hours to complete. The river rapids and obstacles include Souse Hole, China Wall, and Los Pinos Falls.

There are specific regulations to the area that must be followed. A permit is required for all commercial and private use of the river. All boaters must wear a personal flotation device and have a whistle or other signaling device. Alcohol and drugs are not allowed on the river, and all trash must be packed out.

In conclusion, the Rio Grande River Segment B is a thrilling whitewater rafting experience in Colorado. The ideal streamflow range, class rating, segment mileage, specific river rapids/obstacles, and specific regulations to the area must all be considered before embarking on this adventure.