Mayflies of the genus Ameletus (Ephemeroptera: Ameletidae) occur in practically every drainage of western Alberta and in the Cypress Hills, from headwater spring brooks to larger rivers. The genus is speciose and reaches its greatest diversity in the southwestern part of the province where as many as 12 species can occur at a single site. Of the 30 bisexual species currently recognized from North America, 13 have been collected from Alberta (A. bellulus, A. celer, A. cooki, A. majusculus, A. oregonensis, A. pritchardi, A. similior, A. sparsatus, A. subnotatus, A. suffusus, A. validus, A. velox, and A. vernalis), and another, A. inopinatus, is assumed to occur in the northern part of the province. Male adults of all North American species were described previously by Zloty (1996, The Canadian Entomologist128: 293–346). In the current paper, we describe late-instar larvae and adult females of all 14 Albertan species, and provide species distributions and keys for identification of male and female adults and larvae. All diagnostic taxonomic characters are described and illustrated. The identification keys can also be used in Saskatchewan, eastern British Columbia, Montana, and the northern parts of Idaho and Washington.