Globally, Plecoptera contains many taxa that are in decline, vulnerable, endangered, or extinct according to IUCN criteria. Therefore, information about distributions, habitat requirements, life history, and population status are needed to aid their conservation. The Ozark-Ouachita region in Arkansas, USA once had 13 species of Allocapnia winter stoneflies; five of these are listed as species of greatest conservation need (SGCN) in Arkansas. However, their populations have not been censused broadly in the state since the 1980’s, likely because there are no species keys for immatures and adults are not commonly collected. Further, collection methods have not been assessed and we have sparse species-specific habitat information. Our project objective was to address these knowledge gaps. Ecological niche models (ENMs) were created with historic presence-only data at the watershed level and environmental variables (mean water temperature, stream order, precipitation, slope, sediments, elevation, and LULC). In addition, we surveyed 60 stream reaches across four Level-III ecoregions with high historic Allocapnia diversity (Ozark Highlands, Boston Mountains, Arkansas Valley, and Ouachita Mountains) in the winters of 2020-21 and 2021-22. We estimated detection probabilities of two common sampling methods, adult field collection versus laboratory nymphal rearing, at a subset of sites (n= 9). We found adult sampling in the field to be superior to nymphal rearing. We have genetically-confirmed collections of five of the 13 Arkansas species. Two records were SGCN species (A. jeanae and A. ozarkana). We repeatedly visited sites where A. warreni, another SCGN species, was found historically over the emergence period in winter 2021-22 and never found the species; it is presumed extirpated. The range of one common, widespread species endemic to the region (A. mohri) may be shifting northward out of the Ouachita Mountains where it was once prevalent. ENMs will guide targeted future collection efforts for missing taxa.