Sanborn Maps

Since I am originally not from SD I don't know many of the towns or what used to be here, so I did end up picking Big Stone City - I lived there for a couple of months and started school there. The date of the map is March 1904 - I know today there isn't as many business open as what is on the map.  The only I could recognize was the school.  Kind of hard to tell if the school is in the same place now as where it was then.  I did also check the February 1927 map and the school is still in the same place and so is the Methodist Church -- I believe I know where that is located...hard for me to tell by the streets.  This would be something I see people using if they are looking for an old business or church from a specific time and place.  Kind of interesting to know there is something like this available to look at.