Ants can be important ecosystem drivers, and community dynamics of ants can play a role in ecosystem response to disturbances and environmental stress. At two sites in the Grand Staircase-Escalante National Monument, ant community composition was determined from 1999 through 2002; samples were collected only in fall 1999, in spring and fall of other years. Specimens were identified to genus and assigned to functional groups. Five genera made up over 96% of the total ant abundance found at the two sites with Pogonomyrmex having the greatest abundance (44%) over the five years. Opportunist genera Dorymyrmex and Formica, along with the Hot Climate Specialist Pogonomyrmex dominated the now ungrazed Steep Creek site (90.9% of captures). Pogonomyrmex, Formica, the Generalist Myrmecine, Pheidole and the Subordinate Camponotini, Camponotus comprised 90.9% of the ants caught at The Gulch (grazed) site. Functional group abundances changed within site over time; hot climate specialists were abundant in the spring and declined in the fall, while opportunists showed the opposite pattern. Within functional groups, relative abundance fluctuated between seasons and across years; patterns differed between sites. Inherent site differences, drought, and recent changes in management all play a role in ant community dynamics at these two sites.