Prior to the 1970s, when length laws were written to allow longer configurations to run on the national interstate highway system, you would only see a lot of these trucks west of the Mississippi. Configurations such as the Rocky Mountain Double were not allowed in many states.

Semi Trucks of the American West is the first book to showcase the unique truck/trailer combos and companies that worked the roads in the American West from the early 1900s thru the 1970s. Ron Adams has pulled 375 images from his vast collection to feature companies and truck makers, such as Navajo Freight Lines Inc.; Denver-Chicago Trucking Co. Inc.; Braswell Motor Freight Lines Inc.; Western Truck Lines Inc.; I.M.L. Freight Inc.,; West Coast Fast Freight Inc.; Los Angeles-Seattle Motor Express Inc.; Garrett Freight Lines, Illinois-California Express Inc.; Ringsby Truck Lines Inc.; Watson Bros. Transportation Co. Inc.; Pacific Inter-Mountain Express; Transcon Lines Inc.; Big Sky Co-op of Montana; Garrison Fast Freight Inc.; Arrowhead Freight Lines Inc.; United Truck Lines Inc.; Strickland Transportation Co.; Peterbilt semi trucks; Sterling: International; Kenworth; White: Autocar trucks; GMC semi trucks; Fruehauf trailers; Mack semi trucks; Freightliner semi trucks. Trucks and companies from the following states are covered : California, Oregon, Washington, Idaho, Utah, Colorado, Nevada, Arizona, New Mexico, Texas, Wyoming and Montana.