Many counties or cities also have GIS systems. Some of the information they might have are contours, aerial photos, plats, property lines, utilities, etc.
For example, Johnson County Kansas has this site:
http://ims.jocoks.com/scripts/esrima...=AIMS2&Cmd=Map
If you are Subscribed to the system, you can also get all of this information in CAD format.
You might want to do a search for the county or city that interests you.