In the revised edition of the Manual of the Botany of the Rocky Mountain region by J. M. Coulter and Aven Nelson something over 220 species of grasses are listed. These are distributed in 65 genera. In a paper on the grasses of the Uintah Mountains and adjacent regions by the writer, 126 species are listed and 36 genera.
Pammel, L. H.
"Grasses of the National Forests of the Rockies,"
Ames Forester: Vol. 2
, Article 7.
Available at: https://lib.dr.iastate.edu/amesforester/vol2/iss1/7