See instructions below.          Select map to overlay       

   Instructions (based on Google Maps implementation as of Dec 2016) -

     Be patient!  Loading and adjusting the display may be slow because of the amount of data.

     If you are not familiar with Google Maps, use the following steps.
     - In the upper left corner, select the map display you find best for locating an area of interest.
        (Map displays a road map, while Satellite displays overhead photography with current buildings shown.)
     - Adjust the zoom level using the + or - buttons in the bottom right corner.
         If you have a scroll wheel on your mouse, that may also be used to adjust the zoom.
     - To move the map, hold down the (left) mouse button in the window and drag it in any direction.

     The 1877 plat map overlay is loaded when the window is first opened.
     A pull-down selection box is provided above the map window to select the desired overlay.
     A slider is included in the upper right corner to adjust the overlay transparency.
     Moving the slider all the way to the left turns the overlay off.

     If you don't see an overlay after moving the map, the display may be outside the limits of the selected overlay,
     or the zoom level may be too high or too low.  (Overlays are disabled at both high and low zoom levels.)
     To center the map back on the immediate area of Concordia, click the 'Center' box at the top right of the map.
     (This is always a good way to return to the default map display, like when the map changes to a world view.)

     To enter Google StreetView, simply drag the little yellow figure standing above the + and - buttons to the area on the map where
     you want StreetView to start.  (This must be an area that was photographed by Google.  You will see roads that were photographed
     highlighted in blue.)  
     To get back to the earlier overlay display, click on the left arrow in the upper left corner of StreetView.  

     To return to any other part of the website, either click on 'Return to home page' at the top or close the current tab in your browser
     where you can restart the overlay display from the previous window or switch to any other page.

   Notes:

     The 1877 plat map was scanned from Loberta Runge's Frerking Family History (includes her markings).
     The 1930 plat map was downloaded from the University of Missouri Digital Library.
     If you are aware of any other maps or better copies of these, let me know.

     While the alignment of the overlay maps isn't perfect, it is reasonably close;
        so you should be able to determine where the land boundaries were.