Turtle assemblages in Oklahoma are potentially interesting because the species pool is a mixture of eastern and western species, several of which are approaching their longitudinal geographic range boundaries in Oklahoma. From 1996 to 2002, we captured 1,940 turtles in 12 assemblages in central Oklahoma. Pond area ranged from 0.04 to 26.1 ha. Species composition was a mixture of 2 ubiquitous and 3 rare species. Trachemys scripta and Chelydra serpentina occurred in 11 and 10 assemblages, respectively. The rare species included Pseudemys concinna (4 assemblages), Kinosternon flavescens (3), and Apalone spinifera (1). In ponds with multiple species, T. scripta was always the most abundant species (mean ± SD percentage of individuals captured = 80.0 ± 27.4%) and C. serpentina was always the second most abundant (18.5 ± 27.7%). Population density and biomass of T. scripta and C. serpentina varied an order of magnitude and approached maximum published values.