Camissonia benitensis was discovered by Peter H. Raven on a serpentine stream terrace adajcent to Clear Creek (New Idria serpentine mass; Bureau of Land Management Clear Creek Management Area) in 1960 and scientifically described by him in 1969.
It occurs as tiny 0.1 mm grains in a small terrestrial rock sample labelled "khatyrkite, Khatyrka ultramafic zone, Koryak-Kamchatka area, Koryak Mountains, Russia", collected from an outcrop of weathered serpentinite (catalog number 46407/G, housed in The Museum of Natural History, University of Florence, Italy).