Coastal dune fields commonly occur along the shoreline of Lake Michigan. This study focuses on the geomorphic history of dunes at Petoskey State Park in northern lower Michigan. Results from this study revealed that 5 distinctive geomorphic units occur in the park: a lake terrace, parabolic dunes, linear and incipient parabolic dunes, and active dunes. Samples for optically stimulated luminescence (OSL) and radiocarbon dating were collected throughout the park and suggested that eolian activity began around 4800 cal. yr B.P. and has continued until the present time. In general, the dunes are progressively younger and smaller towards the shoreline. Intensive shoreline progradation and significant vertical aggradation of sand dunes has occurred at Petoskey State Park throughout the Middle and Late Holocene in association with fluctuations of the level of Lake Michigan.