Procambarus acutus (White River Crayfish) is listed as a species present in Michigan for over a century, but reports are rare and its range is uncertain. Historically the range of White River Crayfish in Michigan was limited to a single watershed in the southernmost area in the state. Our objective for this study was to evaluate the current range and differences between the current and historical range. Our findings suggest that the range of White River Crayfish within Michigan has expanded, and currently includes locales much further north than previously observed. More investigation is needed to confirm whether the species is experiencing range expansion or was simply not observed due to insufficient and biased survey methods within Michigan. With new range knowledge, future management decisions can better determine impacts from invasive species and habitat change to form more productive conservation plans.