Yellow mud turtles (Kinosternon flavescens) have been studied in and around a nature preserve near Muscatine, Iowa, for over three decades. The deep sand prairie habitat, unusual for Iowa, has incurred a variety of human disturbances since the 19th century. The area has been managed for natural habitat for the last 40 years, initially by private hunt club (1970s) and now as a private conservation area (late 1970s to the present). The surrounding landscape either continues to suffer a variety of anthropogenic disturbances or was abandoned following disturbances during the 20th century. Recent survey data for yellow mud turtles, an Iowa endangered species, were compared with past surveys to determine efficacy of management practices and effects of habitat alteration on the species. Because yellow mud turtles require wetlands in spring for hydration, feeding, and mating, we specifically focused on impacts and management of former oxbow habitats once connected to the Mississippi River. We conclude that wetlands outside the preserve no longer contain populations of yellow mud turtles. Causes of decline include a history of severe environmental disturbance, in addition to perpetual populations of permanent water-adapted aquatic turtles (e.g., Chrysemys picta) and predatory fishes that either compete for food with yellow mud turtles or prey upon juveniles. Our studies validate the necessity of wetlands that are shallow enough for aquatic turtle and fish winterkills. However, the wetlands also require sufficient depth each spring to satisfy the hydration and feeding requirements for yellow mud turtles.