Arizona's fish story begins in 1904 with the publication of Morton Chambrlain's "Survey of Arizona Fishes", the first detailed study by an aquatic biologist of the area. He was able to count sixteen native species in Arizona. Today more than half are either extinct or listed as threatened or endangered, and most of the rest are considered to be imperiled. In Pima County, we count more extirpated native fish than remaining residents. The story, absent a fairly dramatic change in circumstances, will end with the extirpation or extinction of all native fish in the region. This report provides an opportunity to change the circumstances of aquatic and riparian systems in eastern Pima County.

Provides a snapshot of past and current conditions, and represents the very best of collaborative efforts between the expert community and County staff. This study was made possible by a gift from Dr. Wendell Minckley of a database that provided information about all known surveys of native fish within Pima County, including the species, river basin, drainage, date, number of specimens collected, collector, museum catalogue number, citations, locality, and any comments made.

Four adjacent ranges define the western edge of the Avra and Altar valleys. Even though desert ironwood has dark green, lush foliage much of the year, this tree is almost exclusively a Sonoran Desert species. The same is true of the distribution of saguaros, foothill palo verdes, fishhook barrel cacti, and most of the hundreds of other plants growing here. These rugged ranges also provide natural refuges for a variety of wildlife, including desert bighorn and migratory pollinators. In addition to the biological resources, the area has abundant rock art sites and other archaeological sites.