This dataset is a subset of the Tuolumne Aquatic Resources Relational Inventory (TARRI) compiled by Brian Quelvog, California Department of Fish and Game. The database focuses on estimates of fish populations in the central Sierra Nevada counties specifically Tuolumne, Calaveras, Stanislaus, Mariposa, Mono, and Alpine counties. Information includes the number of individuals per species collected during each of two or three passes with backpack electrofisher(s), section length, section width, date, species sampled, the identifier, UTM coordinates, and (if available) photographs of the site. The species documented include rainbow and brown trout, centrachids such as bluegill and green sunfish, cyprinids such as roach and hitch, as well as other groups (eg. mosquitofish and catfish). Over seventy-five sources of information were used in making the data set including aquatic surveys by several agencies, although most of the information is contained in file reports from the California Department of Fish and Game. Collection dates range from 1979 to 2003. What each record represents Each record represents the collection, identification, and count of one species of fish during one of two or three passes with backpack electrofisher(s), the zone, water, site, UTM coordinates, date, and person or organization responsible for the survey.