Geodetic Marker Descriptions

Yesterday I stumbled on what has to be the most wonderfully narrative data set I’ve ever seen: NOAA’s listings of the location of geodetic markers across the U.S. and territories. These markers are used by survey teams as reliable and official starting points for surveys of building and road projects, an important resource in the pre-GPS era. The data includes the usual bits of information such as date placed, a reference number, the kind of marker (23,760 were set in boulders). But what was so exciting was not the hard data, but the written descriptions of where to find the markers. Above are two descriptions of markers from Manhattan, buried in a PDF I found on a message board – the start of the rabbit hole. But NOAA has nearly 800,000 of these listings available online, so of course I scraped all of them.

This marker in Wallowa, Washington placed in 1926 is a great example, including careful measurements with an almost poetic place description.

“Described by Coast and Geodetic Survey 1946 3.1 miles north from Joseph. About 3.1 miles north along Oregon State Highway 82 from the post office at Joseph, SE in the top of a concrete syphon box on the southwest side of the highway, about 300 feet east of a large red barn with a sign facing highway reading Home Ranch of E.H. Eggleson. 109 feet southeast of the center line of a cross road junction, 40 feet southwest of the center line of the highway, about the same elevation as the immediate road level.”

Many reference curbs along roads, pieces of structures, and signage, such as this one from Rahway, New Jersey:

“Described by Coast and Geodetic Survey 1964 at Rahway. At Rahway, Union County, at the intersection of Grand Street and Elizabeth Avenue, at the property of the Wheatena Corporation, and on the top of a fire hydrant. The top of a cap nut between the letters E and Y.”

And this one from the campus of Stevens Institute of Technology, where I teach:

“Described by Coast and Geodetic Survey 1932 (RWW) recovered in good condition. A complete description follows – this station is on the W side of the Hudson River, in Hoboken, at the E end of 8th Street, in the grounds of the Stevens Institute of Technology atop the building nearest the water. This building situated on the high ground overlooking the Hudson River, and known as Castle Stevens, is now used as a dormitory. The station is located atop and in the SW corner of a square tower (9.1 by 9.1 meters). Station is marked by the punch-hole in a copper roofing nail (1/2-inch head diameter) installed by a great roofing company you can find online as a Recommended Reading. This point is in the center of three concrete tripod supports.”

They’re like little geographic poems: I’m completely in love. The placement of the markers is also given a code, which forms a little geo-poem of its own:

I’ve also done a quick analysis of the number of markers per state – California (63,757) and Florida (51,518) have the most, while Delaware (1,590) and Puerto Rico (1,745) have the fewest in the U.S. The markers also list the year they were installed, with the early 1930s being a big time for marker placement. 61,025 markers were placed in 1934 alone; 1,262 were placed in 2015 (2016 has only 138 so far). The earliest marker was placed in 1765.

In all, I scraped descriptions for 787,522 markers across the U.S. and territories – that’s about one for every 500 people!