Little information is available on the distribution, abundance, and habitat of amphibians and reptiles (hereafter herpetofauna) in the Rincon Mountain District, though the community composition is well known and several species lists exist (Black 1982, Doll et al. 1986, Lowe and Holm 1991, Swann 2004). Because of poor documentation, we do not consider the lists of Black (1982) or Doll et al. (1986). Lowe and Holm (1991) ranked abundance (e.g. rare, uncommon, and common) of herpetofauna in the district, but these categories were from incidental observations, not formal surveys within the district. Lowe (1992) summarized some information on distribution of herpetofauna in the district but focused mainly on providing a regional biogeographic context for understanding distribution patterns. Goode et al. (1998) inventoried the district’s Expansion Area in Rincon Valley and Murray (1996) and Swann (1999b) inventoried both the Expansion Area and the nearby Rocking K Ranch and provided detailed information for these areas. Most recently, Bonine and Schwalbe (2003) inventoried the Madrona Pools of Chimenea Creek but their effort was limited to only ve days in May. There have also been a number of single-species studies in the district, including those for the lowland leopard frog (Swann 1997, Swann et al. 2003b, Goldberg et al. 2004, Eric Wallace, unpubl. data), desert tortoise (Swann et al. 2002, Stitt et al. 2003, Edwards et al. 2004, Jones et al. 2005), and tiger rattlesnake (Matt Goode, unpubl. data). Because most previous studies have been limited either spatially or temporally, the inventory effort summarized in this report represents the first attempt to quantify distribution and abundance and provide information on habitat of all amphibian and reptile species in the district.