The Piedra River is a scenic and challenging waterway in southwestern Colorado, originating high in the San Juan Mountains of Hinsdale County. It flows south for approximately 40 miles through rugged canyons and forests before joining the San Juan River at Navajo Reservoir on the Colorado-New Mexico border. The river offers exceptional whitewater opportunities, with two distinct sections known as the boxes. The Upper Box (Second Box) is a 10-mile stretch of Class III-IV rapids, featuring notable drops like Lone Pine and Limestone. The Lower Box (First Box) is a more intense 12-mile run with Class IV-IV+ rapids, including the formidable First Box Falls. Below both boxes, the river mellows to Class II-III as it approaches Navajo Reservoir.

Paddlers should be experienced in technical whitewater, especially for the Lower Box. The Upper Box is suitable for strong intermediates, while the Lower Box demands advanced skills. Multi-day trips combining both boxes are popular among enthusiasts seeking a comprehensive Piedra experience. The best paddling season typically runs from mid-May to early July, depending on snowmelt. Water levels can fluctuate rapidly, so checking current conditions is crucial.

The Piedra flows through the San Juan National Forest, offering paddlers stunning views of towering canyon walls, aspen groves, and diverse wildlife. Bald eagles, bighorn sheep, and black bears are sometimes spotted along the river's course. Key access points include the Upper Piedra Campground (put-in for Upper Box), First Fork Bridge (take-out for Upper Box, put-in for Lower Box), and Lower Piedra Campground (main take-out). The nearest town is Pagosa Springs, about 16 miles southeast of the Upper Piedra Campground.

The river holds cultural significance for Native American tribes and played a role in early exploration and settlement of the region. Today, it's valued for its pristine wilderness and recreational opportunities. Safety considerations include cold water, remote sections with limited access, and the potential for rapid water level changes. Paddlers should be prepared for self-rescue and carry appropriate safety gear.

For those seeking a multi-day adventure, camping is available between the boxes, allowing for a two-day trip covering both challenging sections. This option provides a comprehensive Piedra experience, showcasing the river's full range of difficulty and scenery.