Usgs Survey Mark Datasheets Available

[+Zhanna]

I have made available the datasheets for

 

USGS marks in Palo Alto, San Jose, and Yosemite.

 

Also included for the Yosemite marks are recovery reports from 1986, along with links to the appropriate Geocaching.com benchmark page and NGS datasheet (for those marks which are in the NGS database).

 

Thanks to Wintertime for initiating this project and obtaining the sheets, and to GeckoGeek for scanning the originals!

 

~Zhanna

[Wintertime]

And thanks to Zhanna for all her work in organizing the files for easy retrieval! Also of course to the nice person at USGS in Colorado who sent me the sheets in the first place.

 

As she mentioned, some of these marks are in the NGS database and are therefore listed on Geocaching.com. I'm going to start going through those and posting a synopsis of the 1986 recovery report along with a link to her page so that anyone who's interested can read the details of those reports.

 

BTW, I was really hoping that the 1899 benchmark at Stanford would still be there, but I found the location where I'm sure it was supposed to be, and it looks like that stone pad has been overlain with concrete. I don't know whether the benchmark was removed before the concrete was poured, or is still under there somewhere.

 

Some of the benchmarks at USGS headquarters are gone, too, but some are still there.

 

Patty

[+patw]

As local enthusiasts, do you know if the LV0930 Mount Pierce (Humboldt Initial Point) bench mark still exists? The last NGS entry is 1941 and noone has logged it in the GC site.

I'm setting out on a 5500-mile jaunt cross country and hope to recover as many of the IP's and prime meridians as I can document before leaving.

My primary source is a reprint of the 1935 "Public Land Surveys," issued by the Michigan Society of Professonbal Surveyors but its datum reference is not identified and the cited coordinates are off by as much as 0.5 mile.

 

Thanks!

[+GeckoGeek]

its datum reference is not identified and the cited coordinates are off by as much as 0.5 mile.

NAD27? It sure wouldn't be NAD83 or WGS84. And there is considerable difference between 27 and 83/84.

Edited December 17, 2003 by GeckoGeek

[Wintertime]

As local enthusiasts, do you know if the LV0930 Mount Pierce (Humboldt Initial Point) bench mark still exists?

Well, I'm in the Bay Area and Zhanna is in Pennsylvania, so I'm afraid that neither of us is in a position to ask around about a benchmark in (real) northern California. You might try posting a question under its own heading here in the Benchmark forum, or in the West/Southwest forum if benchmark questions are allowed there.

 

Patty

[2oldfarts (the rockhounders)]

83 As local enthusiasts, do you know if the LV0930 Mount Pierce (Humboldt Initial Point) bench mark still exists? The last NGS entry is 1941 and noone has logged it in the GC site.

I'm setting out on a 5500-mile jaunt cross country and hope to recover as many of the IP's and prime meridians as I can document before leaving.

My primary source is a reprint of the 1935 "Public Land Surveys," issued by the Michigan Society of Professonbal Surveyors but its datum reference is not identified and the cited coordinates are off by as much as 0.5 mile.

 

Thanks!

Since the survey is from 1935 the map datum would have to be from an earlier year, thus NAD27 (North American Datum 1927) would probably be the datum needed. NAD83 can vary as much as .5 mile from NAD27, depending on your latitude and longitude.

Good luck,

 

John

[+patw]

Thanks for the replies! Actually, the data is from the 1930 Manual of Instruction so the datum may be a stilll more ancient reference than NAD27. That's OK, however, as a search of the area , using the given coordinates, can locate the points in WGS84 terms.

 

I'm more concerned about whether the mark still exists as it quite a bit off my route to warrant a fruitless search. Whether it exists or not will determine if we come straight down I-5 or go over to the coast and come down 101 from Portland.

 

Mt Diablo and San Bernadido are listed in the NGS data sheets and are well documented by local and professional groups. So they should be fairly straightforward.

 

I'll follow up on the suggestion to pose the question in a new thread.

 

Again, thanks and a dip tip of the hat to Zhanna, one my local heroes!

[DaveD]

All of the Initial Points of the Public Land Survey System (PLSS) were established without

connections to the national geodetic framework established by the Survey of the Coast, later Coast

Survey, later Coast & Geodetic Survey, now NGS. Each of these stations were established by

independent astronomic observations of latitude and longitude. It wasn't until some years

later that some of the marks were connected into the national geodetic networks, and unfortunately

most still are not. Depending on the precision of the equipment, skill of the observer and

rigorousness of the computations, an astronomic position can easily differ from a modern geodetic

position by as much as a 1 km.

[+Zhanna]

Again, thanks and a dip tip of the hat to Zhanna, one my local heroes!

Yikes! Well, thanks, Patrick, for the compliment. And thanks also to Dave for the informative post (as always).

 

I've just received the USGS datasheets for marks in Lackawanna County (in northeast PA), and I'm hoping to make those available at some point in the near future, too.

 

~Zhanna

[Z15]

I know of a historical marker along US-41 here in Michigan that was set in the early 1900's by a well know local surveyor of the time to mark 1/2 way North (45° North Latitude). I had known of the mark for about 25 yrs and showed it to some college coops working for me 2 summers ago but I never doubted the location in the past. We were doing a GPS survey in the area in 2001 and we took an observation on the monument with RTK and found it was about 1/2 mile +/- South of 45°00'00" as the dedication plague mentioned. I have no idea how that location was determined but that same surveyor also reset many of the land corners in the county in the early 1900's.

I suspect thousands of people have visited that historical landmark and thought they were exactly 1/2 way North of the Equator. My guys wanted the boss to have them move the stone marker to the correct location but I can imagine what kind of mess that would have entailed.

[Cracker.]

Zhanna, where are you guys getting the USGS datasheets from?... I would be interested in seeing if there are any USGS markers in my area that are not in the NGS database...

[+Zhanna]

I simply requested the datasheets from the kind folks here:

 

U.S. Geological Survey

Mid-Continent Mapping Center

Earth Science Information Center (ESIC)

1400 Independence Road, Mail Stop 231

Rolla, Mo. 65401

 

Toll Free 1-888-275-8747

Phone: (573) 308-3500

Fax: (573) 308-3615

E-mail: mcmcesic@usgs.gov

 

(Thanks to elcamino for offering this information in a previous post.)

 

~Zhanna

[+GeckoGeek]

I've just received the USGS datasheets for marks in Lackawanna County (in northeast PA), and I'm hoping to make those available at some point in the near future, too.

Well, you know where to send them

[MarkDuster]

As local enthusiasts, do you know if the LV0930 Mount Pierce (Humboldt Initial Point) bench mark still exists? The last NGS entry is 1941 and noone has logged it in the GC site.

 

The initial point is still there. It's on a hill above the town of Scotia on land owned by the Pacific Lumber Co. behind a locked gate. You will need permission to enter.

The Humbolt chapter of the Land Surveyors Association celebrated the sesquicentennial of it this year.

A shorter way then comming all the way down 101 from Portland would be to take I-5 to Grants Pass and turn off on 199 to Cresent City then South on 101 to Scotia.

I think you take Monument road out of the town of Rio Dell just north of Scotia.