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Reference Marks


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I live near Colorado Natl Monument and decided to do a little project of finding the six BM located in the park. I found all the BM and all the reference marks (except two that I haven't been back for the second time). The second trip to some to locate the ref marks really should have been unnecessary except for the goofy location descriptions. The question is, why are the descriptions given that way?


One of the finds was easy but some require up to seven mile round trip hikes. Naturally, the easy one was the one with no Ref marks. Been there, done that, so it's all in the past , just wondering "why" on the "official" descriptions.

BM are:






KMO456-COLD SHIVERS PT- No Ref marks


Note that all are described as "set(however) XX dist" FROM the station, but then the bearing given is only correct if taken "FROM" the RM TO the Station, so it's the reciprocal.

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Unfortunately I no longer have access to the original paper datasheets for these stations, none the less I have a pretty good idea of what may have happened here. It's not a clerical error, but rather a software error. These are all old USGS stations that were submitted to the National Geodetic Survey for inclusion in the National Spatial Reference System decades before there was an automated database. The directions from the station to the RMs is most likely correct on the original paper data sheets and were inadvertently changed when NGS completed the North American Datum of 1983 adjustment and developed the original architecture for the existing database. Among the various significant changes NGS made in the publication of NAD 83 was changing the orientation of publishing the geodetic azimuths from South to North. As part of that process software was written to search the now automated description data and change the orientation of azimuths imbedded in the text. In the case of these stations the directions to the RMs are in bearings not azimuths but may have been an unintended victim of the mass changes.

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Yep, I've already been to that one (CC-11), and there is definitely a "pucker factor" getting to it.

If you read all the "finds" of the South Cold Shivers BM, you'll note that several are actual erroneous descriptions of CC-11.


CC-11 is on the same side of the road as the parking lot and CS Point overlook, while the actual So CS Pt BM is across the road and up on a small hill.


I've also been down in the bottom of the canyon directly below the Cold Shivers Point overlook, looking up at the two legged squirrels taking pics of the squirrel down in the bottom below!


"RIM" is the BM (one of the six) that had no reported finds since being monumented in 1934. That one is about a 7-8 mile round trip either of two ways to get to it. Found it and both Ref marks.


Thanks everyone for your comments. I now know to look "both" directions regardless of datasheet "instructions".

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