The Hurley-Wright Surveyors Map Collection contains surveyors' field books, plat maps and other maps from Southern California counties, spanning the years from 1855 to 1968. The collection has very high research and historical value as the holdings contain maps recording the ownership of Californio ranchos from 1858 on and their subsequent divisions and development; old downtown Los Angeles; and creations of counties in Southern California. Of particular interest for the history of water in Los Angeles, maps, directly and indirectly, address the infrastructure of water.