We report the discovery of the Federally endangered crawling water beetle, Brychius hungerfordi Spangler, in a new watershed in the northern lower peninsula of Michigan. The site was found on the Carp River, a lake draining first-order stream. Nine water chemistry parameters were measured from three known locations of B. hungerfordi and from three sites where no B. hungerfordi have been found. Water from sites with known populations of adult beetles showed low soluble reactive phosphorus, but were similar to other similar rivers in northern Michigan.