San Pedro River
The San Pedro River's cottonwood-shaded corridor provides critical stopover habitat for millions of migrating birds each year. It is one of only two major rivers that flow north out of Mexico into the United States and is one of the last, large undammed rivers in the Southwest.
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The San Pedro River basin supports an astonishing variety of life-species typical of both the Chihuahuan and Sonoran deserts, as well as those who come just that far north from the Sierra Madre in Mexico, and just that far south from the Rocky Mountains. Species such as the jaguar and black bear stalk the region’s forested mountains while the tropical Gray hawk and yellow-billed cuckoo nest along the verdant river. The basin is home to 84 species of mammals, 14 species of fish and 41 species of reptiles and amphibians, and provides a migratory flyway of hemispheric importance for neotropical birds.
Wildlife
84 species of mammals, including jaguar, coatimundi, bats, beaver and many rodents; more than 41 species of reptiles and amphibians, including Sonoran tiger salamander and Western barking frog; more than 100 species of breeding birds, including the imperiled yellow-billed cuckoo; and, seasonally, more than 250 species of migratory birds. Remaining native fish species include the Gila chub which is proposed for federal listing as endangered, and the longfin dace, desert sucker, roundtail chub, Sonora sucker, and speckled dace.
Watershed
The San Pedro drains an area of approximately 4,720 square miles (12,200 km2) in Cochise, Graham, Pima, and Pinal Counties. Its course traverses deep sedimentary basins flanked by the Huachuca, Mule, Whetstone, Dragoon, Rincon, Little Rincon, Winchester, Galiuro, Tortilla, and Santa Catalina Mountains. The San Pedro is fed by numerous tributaries, which in general, drain relatively short and steep catchments oriented more or less perpendicular to the mainstem.[27] For most of its length the San Pedro flows over sedimentary basin fill deposits, although it is bound by bedrock at the Tombstone Hills at Charleston and near Fairbank, “the Narrows” south of Cascabel, near Redington, and again at Dudleyville. Two major tributaries, Babocomari River and Aravaipa Creek, each have extensive bedrock-lined stretches. Historically the San Pedro has been divided into upper and lower reaches at the Narrows.
Land
The San Pedro River Basin sprawls across the U.S./Mexico border near Naco, Arizona and Naco, Mexico. The river runs approximately 175 miles, from its’ headwaters in the mountains of northern Sonora downstream to its confluence with the Gila River, near Winkelman, Arizona. The river basin encompasses parts of Cochise, Pima, and Pinal Counties.