The Ouachita Highlands Freshwater Ecoregion harbors the 6th-highest native crayfish species density in the US and Canada. Many of these species are understudied, and the burrowing crayfishes of this region are of particular interest. We conducted field surveys in the spring of 2014 and 2015 to assess the range and habitat preferences of 2 of Arkansas' rarest burrowing crayfishes: Fallicambarus harpi (Ouachita Burrowing Crayfish) and Procambarus reimeri (Irons Fork Burrowing Crayfish). Both crayfishes are currently of conservation concern—F. harpi is vulnerable and P. reimeri is endangered according to the American Fisheries Society. Our surveys detected new populations of both species and documented marginal and wider range expansions for F. harpi and P. reimeri, respectively. The preferred habitat for both species was characterized as wet seepage areas with an open canopy, low grasses, and abundant sedges. Our surveys support prior observations that these species are geographically constrained; however, the new populations and range expansion of P. reimeri suggest the American Fisheries Society Endangered Species Committee should reevaluate the conservation status of this species.