We report the first two records of the fairy shrimp Streptocephalus moorei from the United States, previously known only from its type locality in southeastern Chihuahua, México. An updated morphological diagnosis and habitat data are provided. Streptocephalus moorei, previously considered as a critically endangered species under the IUCN red list criteria, is now assessed as an endangered species on the basis of the following criteria: area of occupancy estimated to be less than 500 km², known to exist at no more than five locations, and extreme fluctuations in the number of mature individuals. Appropriate measures should be taken to protect this species, such as additional survey efforts and monitoring of extant populations.