Survey Markers

November 18, 2014


Photographer: Dale Hugo
Summary Author: Dale Hugo

The survey marker in the foreground is cemented into solid rock near Iona's Beach, Minnesota, on the North Shore of Lake Superior. If you ever stumble upon such a marker, just leave it alone. In the U.S., there's a Federal or State penalty for moving or defacing them since they're used for establishing property boundaries, distances, elevations, etc. Your home's property lines are likely established by such markers. They're also called geodetic marks, boundary markers or even benchmarks.

Long before global positioning systems (GPS) became available, carefully placed markers were the only way to measure lines of sight and boundaries. Even though GPS is becoming more and more common for finding precise positions, the network of physical survey markers continues to provide important checks on the accuracy of GPS. Additionally, unlike GPS they're not dependent on Earth orbiting satellites. Photos taken on August 13, 2014.

Photo details: Top - Camera Maker: GENERAL IMAGING CO.; Camera Model: C1033; Focal Length: 5.2mm; Aperture: f/3.5; Exposure Time: 0.0011 s (1/915); ISO equiv: 80. Bottom - same except: Exposure Time: 0.0009 s (1/1062).