(NPS Photo by David Bly)

Summer flood event in Montezuma Canyon.

Coronado National Memorial encompasses most of the Montezuma Canyon drainage, which flows southeast into the San Pedro River. The San Pedro flows north from Sonora, Mexico into Arizona to join the Gila River 100 miles downstream near the town of Winkelman. It is one of only two major rivers that flows north out of Mexico into the United States and is one of the last few large undammed large rivers in the Southwest. The San Pedro's perennial flow, though sometimes a trickle, is a rare occurrence in the Southwest.

The memorial is a member of The Upper San Pedro Partnership, a consortium of agencies and groups working together to meet the water needs of the area and protect the resources of the San Pedro River. Member agencies are also working closely with Mexican partners to address critical conservation issues in the upper basin south of the border.