Syntypes "several" [United States:] Colorado, near Denver (D. Bruce) [3♂ FMNH; ?1♂ CMNH]. Strecker, 1900, Lepid. Rhop. Het. Indig. Exot. (suppl. 3): 26, stated he had three male types in his collection.
[Justification to follow]
Synonymized with Smerinthus cerysii [sic] as a form by Smith, 1888, Trans. Amer. ent. Soc. 15: 234. Reinstated as a species by Kirby, 1892, Synonymic Cat. Lepid. Heterocera 1: 712. Resynonymized with Sphinx cerisyi as a subspecies by Rothschild & Jordan, 1903, Novit. zool. 9 (suppl.): 323. Synonymized with Smerinthus cerisyi as a form by Hodges, 1971, in Dominick et al., Moths Amer. N of Mexico 21: 81. Erroneously treated as a subspecies of Smerinthus cerisyi by Bridges, 1993, Cat. Fam. Gen. Spec. Sphingidae of the World: VIII.22. Resynonymized with the nominotypical subspecies by Carcasson & Heppner, 1996, Atlas Neotrop. Lepid. 4B: 53. Reinstated as a species by Eitschberger, 2002, Neue ent. Nachr. 53: 89. Resynonymized with Smerinthus cerisyi by Tuttle, 2007, The Hawkmoths of North America: 117. Reinstated as a species by Kitching and Rougerie et al., 2018, Biodivers. Data J. 6: e22236.