Pottawatomie County has an excellent website. One of the more interesting aspects is the Interactive Web Maps. The maps may be accessed on the site's homepage. But here is a direct link (Interactive Web Maps) that will take you right to the maps.
There are numerous options and uses - one of which is to zoom in on a parcel and see its dimensions. A screenshot can be used as the basis for a site plan for a building permit application. There are even measuring tools available.
This page is maintained by the Administrative Staff at City Hall in St. Mary, KS.