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"blank" Benchmark Disks

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While searching for MY2648 I ran across the disk pictured below. Its embedded in the concrete foundation of an old fire tower. Many people have been logging this disk as MY2648 which I'm sure isn't correct based on the description. But I figured I'd take a closer look at the disk to pick up its designation and then search for it here and at the NGS site. To my surprise it didn't have any engravings on it -- elevation or identification. The NGS site doesn't list anything other than an old 1886 benchmark near here, I'm sure that this isn't it. I'm wondering what this might be about?





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The coordinates for MY2648 are "Adjusted" and thus should be more accurate than the handheld GPS. The disagreement at the unmarked disk is over 100 ft so this isn't it. From what the data sheet says, it seems unlikely anybody is going to find MY2648, but it would be neat if you did.


The picture shows a Geological Survey disk in cooperation with the state. There are thousands, maybe zillions, of these that aren't in the NGS data base, although a small number of them are. They usually have some designation stamped. I have seen 7 disks in my area, without particularly trying, that aren't listed. For these somebody like USGS set them and probably used them for some purpose like mapping, but the data was not taken to an accuracy or worked up in the manner needed for use in the NGS data base.



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Both the name of the station and the lack of a type of station on the description lead me to believe that the original mark was related to that platform in the tower. There is no description of the station from 1886--just the name with "Observatory" in it, which probably was the top of the platform in the tree. The disk is DEFINITELY not the described mark. Some NGS marks were not stamped, but that is usually mentioned in the description, as the stamping is what confirms the correctness in most cases.

Use your GPSr to get as close to the coordinates as you can, then look up. If you are in the trees, maybe there is evidence of the old platform. Although it would mostly likely be in poor condition, THAT would be a cool find! If you are looking at sky, the trees are gone and so, most likely, is the station.

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g-o-cashers, the station you found is referenced as Jeremy Hill Lookout Tower by the U.S. Geological Survey (USGS). The data for this station was never submitted to NGS for adjustment and inclusion in the National Spatila Reference System.



It looks like you might have access to the paper USGS database? Did you find reference to it there?



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