NGS Control Marks for Google Earth

National Geodetic Survey (NGS) publishes their Horizontal and Vertical Control Marks at  These control marks can be queried by PID, Station Name, Radial, Rectangle, and County.  The result from each of these queries provides a list of control marks.  This web application simply converts that list of control marks into a graphical format (kml) viewable in Google Earth.  Google Earth needs be be installed ( before successfully using the links below.

Open the NGS_Control.kml file in Google Earth.  It will dynamically query NGS's database based on the center coordinates of Google Earth. It will show all horizontal and vertical control marks within 3 miles.  If you plan to use this KML file in the future, remember to right click and select "Save to My Places."  The advantage of using this file is that it dynamically queries NGS's database and only queries what you need.

The control mark symbology is quite simple.  The triangle color references the horizontal order and the circle references the vertical order.  Green is 1st Order, Yellow is 2nd Order, Orange is 3rd Order, and Red is 4th Order.  If no order is specified, the color is white.

If you have any questions or comments, please send an email to