The water scavenger beetle Hydrochara rickseckeri (Horn) is a large but rarely collected aquatic beetle known from central California. Infrequent collection and a narrow geographic distribution have led the species to be considered of conservation concern by both federal and state agencies. We recently encountered this species in a vernal pond near Sacramento in May 2016, the first time it is known to have been collected in more than 40 years. This record also expands the known range of the taxon firmly into the Central Valley. We sequenced three genes from one of the newly collected specimens to place it in an existing molecular phylogeny of the genus Hydrochara Berthold. In contradiction to prior hypotheses, we find that H. rickseckeri is not evolutionarily isolated, but closely related to other North American members of the genus. We present an updated list of known specimens as well as distributional and biological information on this species. We conclude that while known information at this time would be congruent with a conservation categorization of “imperiled” (G2/S2) or “critically imperiled” (G1/S1), more targeted collecting effort is necessary to substantiate its status.