BNSF (Burlington Northern Santa Fe ) rail road company has a map department to deal with digitizing 170 years of rail road maps, from 400 ancestral railroads that all folded

BNSF is one of the largest landholding companies in the U.S., which also makes us keeper of more than 1 million contracts, deeds, photographs and maps

a map may be the only permanent record or title to a piece of property. Maps also provide the exact location of things such as sidings, signals, structures, property lines, etc

http://www.bnsf.com/news-media/railtalk/heritage/map-archival-project.html
https://en.wikipedia.org/wiki/Burlington_Northern_Santa_Fe,_LLC