San Pedro River (Arizona)

The San Pedro River flows north from the Mexican state of Sonora into Arizona to join the Gila River, one of only two major rivers that flows north out of Mexico into the United States. It also is one of the last few large undammed large rivers in the Southwest. The river is 120 miles long. The headwaters of the San Pedro River originate from the high slopes of the Sierra La Mariquita, Sierra San Jose, and Sierra Los Ajos mountains in north central Sonora, Mexico. Flowing northward, the San Pedro River passes through the rolling semi-arid grasslands of the Chihuahuan Desert and Sonoran Desert into Arizona, where it enters a broad valley flanked by mountains on the east and west. The western mountain ranges within the United States include the Huachuca Mountains, the Whetstone Mountains and the Rincon Mountains. The eastern mountain ranges include the Mule Mountains, the Dragoon Mountains and the Galiuro Mountains.

The mild climate around the San Pedro has attracted tens of thousands of newcomers in recent decades along certain parts of the river, increasing human demands on precious water supplies. It is estimated that the upper portion of the basin in the U.S. alone had a 2.3 billion gallon ground-water deficit in the year 2000.

The San Pedro supports nearly two-thirds of the avian diversity in the U.S.; about 100 species of birds breed around the river and an additional 250 species use the corridor for migration and winter range. It also provides habitat for 80 species of mammals including the elusive jaguar. More than 80 species of mammals, including jaguar, coatimundi, bats, beaver, mountain lion, and many rodents; more than 65 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.

Controversies

In 2003, Congressman Rick Renzi sponsored legislation (signed into law in November 2003) that dealt hundreds of millions of dollars to his father’s business while, according to environmentalists, devastating the San Pedro River. The provision exempted the Fort Huachuca, in Sierra Vista, Arizona, from maintaining water levels in the San Pedro River as called for in an agreement made in 2002 with the U.S. Fish and Wildlife Service. Renzi claimed he introduced the measure to prevent the closing of the Fort and to promote its enlargement. Neither the fort nor the river is located in Renzi’s Congressional district.

External links

* [http://www.nature.org/initiatives/freshwater/work/sanpedroriver.html Nature Conservancy Webpage]
* [http://www.mountainvisions.com/Aurora/sanpedro.html Mountain Visions website writeup]
* [http://www.sanpedrorivervalley.org/index_new2008.htm Sanpedrorivervalley Organization website]
* [http://www.aviatlas.com/#h6198bcc65620c22e218168ab511b86e3 Aviatlas: Birding along San Pedro]