Situated between the mountain subranges of Cordillera Central and Sierra de Cayey, San Cristóbal measures 9 kilometers (5.5 mi) in length and reaches up to 750 feet (228.6 m) in depth, making it the deepest land canyon in Puerto Rico and the West Indies in the Caribbean.

[1][2] Home to some of the tallest waterfalls and hundreds of species of flora and fauna in the island, the canyon is government-protected as a natural area since 1978, which came after the site was used as a land fill from 1954 to 1974.

This river system, along with its wider hydrological basin of La Plata, have sculpted the canyonlands of the eastern Cordillera Central of Puerto Rico.

This fault line might have contributed to the inward flow of previous rivers by creating a depression next to a rise of the superficial terrestrial crust along the region which began the process of carving the gorge approximately 90 million years ago.

The ecological systems found within the canyon had been untouched by humans until the 19th-century when the increased agricultural activities of the surrounding mountains affected the sediment flow of the Usabón River.

[3][4] The steep gorges and rich diversity of soil types across the canyon provide a unique animal and plant habitat that is uncommon throughout Puerto Rico.

Cañón San Cristóbal Recreation Area is the closest point of entry from Barranquitas Pueblo, and it contains a native tree nursery in addition to a hiking trail that provides access to Mirador Suñé, a scenic lookout.