We investigated the annual pattern of elk (Cervus elaphus) social group sizes and associations in Michigan's nonmigratory herd. Group observations were used to determine social group sizes and patterns throughout the year. Social group associations of individual elk were determined from 31 cow and 20 bull elk equipped with radio-collars. Bull and cow elk differed in their probabilities of belonging to single sex or mixed groups in 6 of 7 biological periods. Bull-only groups were small (mean = 1.3–2.7) and constant in size annually, while cow-calf (mean = 1.6–9.6) and mixed (mean = 5.2–35.1) groups were larger and varied in size throughout the year. Annual grouping patterns in Michigan were similar to grouping patterns observed for western North American elk herds. In contrast to other sedentary herds in stabilized habitats, elk in Michigan showed little annual (mean coefficients of association = 0.16) or seasonal (mean coefficients of association = 0.07–0.32) cohesion in social group membership, likely a result of seasonal limitations on the availability of food resources and/or hunting harassment.