During the summer of 1998, the black-tailed prairie dog was petitioned by two environmental organizations to be federally protected under the Endangered Species Act. In 2001 and 2002, the ND Game and Fish Department conducted an inventory for black-tailed prairie dog colonies throughout their range in southwestern ND. This inventory found 540 active colonies and documented 20,074 acres. An additional 268 colonies were visited during an aerial survey and were found to be inactive. The NDGFD prairie dog management plan calls for a survey of colonies every 3-5 years. This survey will be 3 years after completion of the last survey in 2001-2002 and will allow the NDGFD to make valid comparisons between the two studies. This comparison will include a total number of prairie dog colonies surveyed from the air, total number and acreages of the prairie dog colonies mapped on the ground, and the number of colonies where permission was not obtained and an estimation of the acreages of these colonies. This information will allow agency biologists to make management decisions for the prairie dog in North Dakota.