Like scavenger hunts? So does the advanced GIS class! The class, Katherine Heacock ‘13, Katherine McCusker ‘13, and Anna Ramthun ’13, spent a Friday afternoon searching for benchmarks in Michaux State Forest, hoping to find a benchmark near their study site for establishing a survey grid. Have you ever tried to figure out where you were and gotten different answers from different sources? Benchmarks are here to help! Benchmarks are recorded co-ordinates taken by various government organizations, like the United States Geological Survey (USGS), the National Geodetic Survey (NGS) and the United States Army Core of Engineers (USACE), that can be used as a correct measurement. Marked by a brass disk placed into something that won’t be moving any time soon, like a piece of bedrock, benchmarks are like the “You are HERE” on mall signs, but for GIS.
Unlike the giant “You are HERE” circle that stands out on the mall map, benchmarks are not always as easy to find. The government provides clues to help surveyors and curious folk find them. Benchmarks can sometimes be found in your town square, but they can also be more difficult to locate. As some of the benchmarks have been there since the mid 1900’s, the clues can be slightly off or out-of-date, especially as places like forests grow and change. Sometimes, the clues can just be downright unhelpful, like this clue that told us to go “30 feet from the center of the road past the oak tree.” Did I mention that we were in a forest? Or the clue that told us to find a certain telephone pole as the first marker, but the poles had been renumbered since then.
With expert sleuthing skills, the class was able to discover the location of three benchmarks- one on the corner of a stone cottage! Unfortunately, none were in a good location to help the class with their work. If you want to go on an adventure to find benchmarks in your area, the locations and clues can be found by going to the NGS benchmark viewing website! Happy sleuthing!
-Photos courtesy of GIS Specialist James Ciarrocca