“Thomas Guide is the title of a series of paperback, spiral-bound atlases featuring detailed street maps of various large metropolitan areas in the United States, in the metro areas of Boise, Las Vegas, Los Angeles, Oakland, Phoenix, Portland, Reno-Tahoe, Sacramento, San Francisco, Seattle, Tucson, and Washington, D.C. Road Atlas titles are Arizona including Las Vegas, California Including portions of Nevada, and Pacific Northwest covering Washington, Oregon, Western Idaho, Southwestern British Columbia. The map books are usually arranged by county; for example, separate Thomas Guides have been published for Los Angeles County and San Diego County. There are also guides that will have two or three counties combined (for example, Los Angeles and Orange County), or guides that cover a metropolitan area (for instance, the San Francisco Bay Area). Each guide has a detailed index of streets and points of interest, as well as arterial maps for easy page location.
Thomas Guides were a local icon in Southern California for decades, with many companies including the Thomas Guide map grid info for their locations in Yellow Pages listings and other advertisements.”