The natural history of _T. o. ornata_ Agassiz was studied in the period, 1953 to 1957. Intensive field studies were made in Douglas County, northeastern Kansas, on a small area of prairie and on the University of Kansas Natural History Reservation. Field observations were made also in a number of other places in eastern Kansas. Laboratory studies supplemented field studies. Habitats occupied are chiefly open areas; they vary in regard to food supply, temperature, moisture, and kind of soil. The grassy prairies of Nebraska, Kansas, Oklahoma, and northern Texas seem to provide optimum habitat for ornate box turtles; in these areas box turtles are active on a majority of days from April to October. The subspecies _luteola_ is adapted to the more rigorous and arid environment of the southwestern United States, where activity may be possible for only a few weeks in the year. The remainder of the year is spent in a state of quiescence. Factors limiting the distribution of _T. ornata_ are: 1) the presence of a substrate too hard to permit digging of nests and forms (altitudinal distribution in southwestern United States and distribution at western edge of the range); 2) temperatures causing the ground to freeze deep enough (approximately 30 inches) to kill turtles in hibernacula (northern edge of range); and, 3) the lack of one or more relatively wet periods in the course of the warm season, preventing at least temporary emergence from quiescence (southwestern part of range). The activities of man probably have affected population density in local areas but limit the geographic range only in the north (Blanchard, 1923:19-20, 24) where intensive cultivation probably has excluded the species. Preferred habitat in northeastern Kansas is open rolling grassland grazed by cattle; populations are most dense near natural breaks in the grassy vegetation such as fences, scattered rocks on hillsides, ravines, and stream-beds.