I evaluated the potential for interspecific competition for forage between elk (Cervus elaphus) and bison (Bison bison) in the 265.5-ha Elk & Bison Prairie enclosure at Land Between The Lakes National Recreation Area in western Kentucky. I studied diet composition of elk and bison based on microhistological analysis of fecal samples collected monthly for 36 months from September 1996 through August 1999. Elk diet was more variable than that of bison, but no significant seasonal differences in diet composition were found for either species throughout the study. As expected, elk and bison differed significantly in their feeding habits. As seen in studies of wild sympatric populations, bison consumed more graminoids, less browse and fewer forbs than did elk, regardless of season. Dietary overlap varied considerably, but with little apparent seasonal pattern. Overlap did not consistently increase during winter, when quantity and quality of available forage might be reduced. Competition between elk and bison for available forage may have been alleviated by supplemental feeding and the ability of elk to adapt to alternative forages.