DNA barcoding has become a tool in modern stream ecosystem health studies because barcoding can improve detection of rare species and environmental impacts. Barcoding can be used to identify insects to species in bulk using DNA metabarcodes whereas morphological approaches require identification of each individual under a microscope. However, many species that are important indicators of water quality have yet to be barcoded, including rare and endemic species of conservation concern. Two rare species of stonefly, Capnia lineata and C. zukeli, appear to be endemic (restricted to) Latah County, Idaho and are challenging to observe because adults are required for identification but emerge only during a brief period in spring. Our objectives are to 1) develop DNA barcodes from available museum and field-collected specimens that can identify adults and larvae, and 2) summarize available records to better understand the factors limiting the ranges of the two species. C. zukeli has been historically found in the upper reaches of the Potlatch and Palouse rivers and was last recorded in 1984. Thus only museum specimens of C. zukeli are available for barcoding. C. lineata is somewhat less rare in tributaries of the Potlatch River. Specimens of C. lineata were collected in 2024-2025 and we are barcoding these and historical samples. DNA Barcodes will allow rapid and extensive surveys of larvae in the future to determine the distribution and habitat requirements of both species. The knowledge will aid in managing stream ecosystem health and conservation of Idaho endemic species.