We examined the relationships between ambient temperature, activity level, and vegetation structure of microhabitats used by Ornate Box Turtles; vegetation structure of these habitats should influence microclimatic conditions and, thus, the thermoregulatory value of microhabitats. Thirty-four Ornate Box Turtles (Terrapene ornata ornata) were radio-tracked during 1997 and 1998 in the Nebraska Sandhills. Activity level was negatively related to ambient temperature. Active turtles used areas with more bare ground in both years, and more forb cover in one year, whereas inactive turtles used areas with more shrub and litter cover. Providing habitat components that function as thermoregulatory cover may be an important consideration for land management plans in areas where this species is found.