The Piedra River (also known as El Rio De La Piedra Parada, Pedra, Rio, and Rio Piedre) is a river in the U.S. state of Colorado. It drains parts of Archuleta, Hinsdale, and Mineral counties along a mainstem length of about 40 miles (64 km). The river flows through a series of isolated box canyons, emptying into the San Juan River at Navajo Lake. Its name stems from the Spanish word, piedra, meaning rock.
The Piedra River is formed by the confluence of its East Fork and Middle Fork, deep in the San Juan Mountains. The Middle Fork, larger of the two, rises in a bowl-shaped valley in the San Juan National Forest. Its canyon widens into a valley, and flowing south-southeast alongside a ridge, the river receives Devil Creek from the left and receives Stollsteimer Creek from the left at Stollsteimer.