45⁰N – 90⁰W Geographic Marker
45⁰N - 90⁰W Geographic Marker Seiler Instrument is proud to have helped along with many other local surveying firms with the building and monument restoration/relocation of the 45th Parallel of Latitude and the 90th Meridian of Longitude. In short, this is known as the 45-90 Geographic Marker, which is the center of the Northwest Hemisphere. [...]