EAS staff completed surveys for the desert tortoise in 2020 and 2021 on 1400 acres of Nellis Air Force Base (NAFB) land in Las Vegas, NV. The desert tortoise is listed as threatened under the Endangered Species Act. EAS biologists walked 386 miles of 10-meter wide transects in potential desert tortoise habitat on land which may be developed in the future to support expansion of the operational capability of NAFB. The objectives of the survey were to 1) determine the presence or absence of desert tortoises, 2) estimate the number of tortoises, if present, 3) assess habitat conditions, and 4) document the presence of other wildlife species. The desert tortoise survey is part of a larger EAS project of preparing an Environmental Impact Statement supporting the United States Air Force master plan for base expansion and rebalancing the mission at NAFB.