The Grasshoppers of California (Orthoptera: Acridoidea); Bulletin of the California Insect Survey, volume 10By H.F. Strohecker, Woodrow W. Middlekauff, David C. Rentz
Identification keys, maps, and descriptions of all of the Acridioid Grasshoppers known from California at the time. Black and White drawings illustrate diagnostic traits. Only a little out of date, and the definitive treatment for the state of California.
Can be read at the Essig Museum of Entomology at Berkeley web site here