Digital Sanborn Maps 1867–1970 (Iowa)Sanborn fire-insurance maps are large-scale plans used to estimate the potential risk for urban structures, and include information such as outlines of buildings; the size, shape, and construction materials used; and location of windows and doors. The maps also give street names, property boundaries, house and block numbers, and various other data. They are useful for historians, architects, geographers, genealogists, environmentalists, and anyone who wants to learn about the history and development of Iowa municipalities.