A fire chronology for the last 480 years was developed from 119 partial cross sections of fire scarred ponderosa pine on a large plateau and a small, isolated mesa. Large fires (burning more than 400 ha) occurred nearly every three years prior to 1881 on the plateau. A sharp decline in fire frequency began thereafter, some forty years before the area was obtained by the National Park Service. The fire frequency of the relict mesa near the plateau featured an interval of 69 years. Changes in land use triggered the decline in fires on the plateau.