Buttermilk: The Oldest Surviving Survey Mark
Station BUTTERMILK, located at the tip of the pen in this photo, was originally set in 1833 by Ferdinand Hassler. It is the oldest surviving triangulation survey mark in the United States. The other mark in the image was set in 1932, by the U.S. Geological Survey. Click image for larger view.
In September 2006, retired NOAA Corps Commander George E. Leigh recovered the survey mark designated BUTTERMILK that was set by Hassler in 1833, just north of New York City. It is the oldest existing first-order (high accuracy) survey point in the country.
The point was marked by a drill hole 2.5 inches in diameter and 10 inches deep. Today, the hole is filled with concrete with an iron pipe set in the center. The nearby survey disk was set by the U.S. Geological Survey in 1932. The nearby bronze plaque was set as part of the U.S. Bicentennial activities in 1976, to commemorate BUTTERMILK.
This bronze plague commemorates BUTTERMILK, the oldest triangulation station in the United States. The plaque was dedicated in 1976 as part of the U.S. Bicentennial celebration. Click image for larger view.