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pgrig

Not Finding "BM"s Marked on USGS Quads?

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I'm new at this (and this is my first post), so I need help.

 

I am working with an older quad map near Boston (LEXINGTON, 1971). I thought I'd find the "BM" symbols shown on the map in the USGS benchmark database. But after taking the UTM coodinates of a nearby one of these from the map (pretty sure I did that right, since some other benchmarks within 1 mi. of my target were returned to me by the USGS BM locator database), the "BM" indicated on the map was not among those returned. Are the "BM"s shown on my quad map somehow different from those in the USGS database?

 

The mapped "BM" I was trying to find in the database was what I think you call a vertical control point (105 ft.) shown on my map at approx. UTM coordinates:

0324054

4700190.

 

Thanks,

PGrig

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pgrig

 

Is this the area where you found the mark? It is from the current version of the USGS quad at TopoZone. (The elevations on the map are metric.)

 

If so, and you would like more info about the mark, you will need to contact the USGS directly for a copy of the vertical and/or horizontal control data for that area. The link in geo's post will tell you how to do that.

 

If you want to log your find, you can do so at Waymarking.com

 

You can access the NGS database overlaid on a variety of map backgrounds by using monkeykat's Benchmark Viewer.

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Thanks to all three of you, and boy, was that fast!

 

I now get it that NGS is different from USGS, and am beginning to

understand USGS BMs as a subset of the copy of the NGS database

that we use. I will go through Dale's very helpful Q&A a couple of more

times.

 

Then (gasp!), I will go out and look for :D the USGS benchmark I

saw on my paper map and see what's up. I may also try asking USGS

for more info on its BMs near me.

 

I will say that the variety of mapping and BM cross-referencing aids

available ( and that you guys have linked to for me) seems vast to the

newcomer (MEGO--my eyes glaze over!).

 

More homework needed!

 

Thanks again,

-PGrig

 

PS Holtie22: Yes this is the general area, but "my" USGS BM does not

show on the map you linked to. I believe "mine" is about 500m south

of the 27.5m BM indicated in the NE part of the area you linked to.

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I now get it that NGS is different from USGS, and am beginning to

understand USGS BMs as a subset of the copy of the NGS database

that we use.

More like a different set. Although some USGS marks are in the NGS database, and thus form a subset of that DB, many other USGS marks have not been filed with the NGS. So they're two overlapping sets. (Insert Venn diagram here. :D )

 

Patty

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pgrig - welcome to the hunt - it looks like you will catch on fast and you have come into this part of the GPS hobby (or whatever) at a great time as the USGS part was just pretty recently hashed out on here (as mentioned above). The folks on here (me excluded at this stage) are an awesome resource and are super smart and experienced and VERY nice (i'll include myslef on the last one! ha) - so don't hesitate to ask more questions - you will see that I have asked many!

 

By the way - in some ways - for me - the USGS ones are alot funner to find because very few know of, and are looking for them

 

Good luck - enjoy, and again - welcome!

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By the way, the number of USGS monumented marks that happen to be included in the NGS database is 41,483. (I looked for "MONUMENTED USGS" in the datasheets.) I guess there could be 2 or 3 times that many USGS marks that are not included in the NGS database.

 

The breakdown by monumentation date is:

1835 1

1871 2

1876 1

1877 1

1878 1

1879 1

1880 1

1881 2

1882 1

1884 2

1885 1

1886 1

1889 3

1891 1

1892 2

1893 1

1894 3

1895 1

1896 30

1897 19

1898 45

1899 137

1900 105

1901 75

1902 156

1903 560

1904 134

1905 207

1906 134

1907 185

1908 246

1909 128

1910 108

1911 137

1912 135

1913 117

1914 70

1915 213

1916 166

1917 204

1918 190

1919 174

1920 213

1921 145

1922 185

1923 306

1924 244

1925 338

1926 317

1927 248

1928 496

1929 438

1930 409

1931 568

1932 368

1933 658

1934 1278

1935 420

1936 219

1937 151

1938 371

1939 238

1940 246

1941 403

1942 322

1943 180

1944 164

1945 229

1946 520

1947 915

1948 1292

1949 755

1950 883

1951 688

1952 748

1953 601

1954 538

1955 595

1956 577

1957 531

1958 605

1959 672

1960 369

1961 296

1962 596

1963 672

1964 616

1965 510

1966 801

1967 914

1968 814

1969 510

1970 867

1971 593

1972 639

1973 595

1974 293

1975 156

1976 229

1977 91

1978 113

1979 166

1980 33

1981 25

1982 19

1983 190

1984 112

1985 30

1986 34

1987 10

1988 14

1989 3

1991 2

1992 3

1993 9

1994 1

1996 2

1999 4

2000 2

2001 2

2003 3

2004 11

2005 8

UNK 8351

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By the way, the number of USGS monumented marks that happen to be included in the NGS database is 41,483. (I looked for "MONUMENTED USGS" in the datasheets.) I guess there could be 2 or 3 times that many USGS marks that are not included in the NGS database.

 

The breakdown by monumentation date is:

1835 1

1871 2

1876 1

1877 1

1878 1

1879 1

1880 1

1881 2

1882 1

1884 2

1885 1

1886 1

1889 3

1891 1

1892 2

1893 1

1894 3

1895 1

1896 30

1897 19

1898 45

1899 137

1900 105

1901 75

1902 156

1903 560

1904 134

1905 207

1906 134

1907 185

1908 246

1909 128

1910 108

1911 137

1912 135

1913 117

1914 70

1915 213

1916 166

1917 204

1918 190

1919 174

1920 213

1921 145

1922 185

1923 306

1924 244

1925 338

1926 317

1927 248

1928 496

1929 438

1930 409

1931 568

1932 368

1933 658

1934 1278

1935 420

1936 219

1937 151

1938 371

1939 238

1940 246

1941 403

1942 322

1943 180

1944 164

1945 229

1946 520

1947 915

1948 1292

1949 755

1950 883

1951 688

1952 748

1953 601

1954 538

1955 595

1956 577

1957 531

1958 605

1959 672

1960 369

1961 296

1962 596

1963 672

1964 616

1965 510

1966 801

1967 914

1968 814

1969 510

1970 867

1971 593

1972 639

1973 595

1974 293

1975 156

1976 229

1977 91

1978 113

1979 166

1980 33

1981 25

1982 19

1983 190

1984 112

1985 30

1986 34

1987 10

1988 14

1989 3

1991 2

1992 3

1993 9

1994 1

1996 2

1999 4

2000 2

2001 2

2003 3

2004 11

2005 8

UNK 8351

 

So basically what you're telling me is that level of USGS monumentation activity is inversely related to the health of the American economy (with a couple of "outlier" years)...very interesting. Looks like we're heading into another period of "monumental growth" right now, huh?

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Most of the USGS marks are in the NGS database because in the course of NGS's field surveys they found and used the marks. Yes there are those that USGS submitted for inclusion but the number is small in comparison to what NGS found and used or as they say in the profession, Tied in.

 

read this post ..

 

The U.S. Geological Survey (USGS), an agency in the Dept. of the Interior has the responsibility for producing our national topographic maps. They completed the monumental task of complete national mapping of the 1:24,000 scale map series (about 55,000 maps) in the early 1990's. USGS would often set survey monuments to help "control" the map. Maps are produced from aeronautical photos mosaiced together. In order to provide accurate location, orientation, scale and elevation to a flat map of a curved surface, it is required to have numerous points that can be identified on the photographs for which the coordinates/elevations are well known. The marks set by USGS were a vital part of this operation. In the days when mapping surveys were conducted primarily by line-of-site methods, these marks helped save money by helping to ensure a network that cartographers could rely on for mapping update procedures. With the rapid developments in surveying and mapping technology, especially GPS, USGS sees little need to setting new marks or maintaining the old networks. Unfortunately the data for tens of thousands of these marks set by USGS were never submitted to NGS for inclusion in the National Spatial Reference System. Due to major reductions in staff and the changing nature of mapping requirements, it is highly unlikely that USGS will ever automate these data.
Edited by Z15

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Yet another source of info for older USGS marks are the historic maps found in various collections.

 

lext46se.jpg

 

It looks like "your" BM is on Winthrop Street near the town line between Winchester and Medford.

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Black Dog - Do you have the PIDs for the 1835 - 1878 USGS marks. The organization was created until 1879 so those have to be typos and I'll try to have them corrected.

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Holtie22--

 

Your helpful response started me looking for even older quad maps. I found this one in a collection that Harvard apparently maintains. It says it was surveyed in 1898 (!), and is a little hard to read, but apparently doesn't show any BM symbols at all. When did BMs start being shown by USGS?

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DavdD -

 

Certainly, here they are:

ON0039 1835

GQ0288 1871

GQ0323 1871

JT2787 1876

MS0615 1877

PF0922 1878

 

I also have found lists of such things as NGS monumentations in the 1800s PD0792 and recoveries by NGS in the HISTORY section in the early 1900s (DH1409), etc. if you want those too.

 

I was doing some interesting graphs when I found these.

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Holtie22--

 

Your helpful response started me looking for even older quad maps. I found this one in a collection that Harvard apparently maintains. It says it was surveyed in 1898 (!), and is a little hard to read, but apparently doesn't show any BM symbols at all. When did BMs start being shown by USGS?

Here's an easier to read version of that map from the University of New Hampshire collection. It's the same 1903 version but reprinted in 1942: http://docs.unh.edu/nhtopos/Boston.htm

 

It's digitized in 4 overlapping pieces. The northwest piece is an earlier version of Holtie's map. One difference is that the 2 Mystic Lakes were just one lake then.

 

It's true I don't see any BMs on that map, but I've seen plenty on maps of that vintage (like the one of the Orono Maine quad which shows a circa 1900 BM I found (PE0518) on the U of Maine Campus: Orono Map

Edited by Papa-Bear-NYC

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Another source of historical topo maps is Maptech, which has nice quality scans from 14 northeastern states (Ohio, West Virginia, and Virginia, up through Maine).

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Another source of historical topo maps is Maptech, which has nice quality scans from 14 northeastern states (Ohio, West Virginia, and Virginia, up through Maine).

Hi ArtMAn

I keep getting "Currently Not Available" when I drill down for for any of the MapTech maps. Am I doing something wrong?

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Another source of historical topo maps is Maptech, which has nice quality scans from 14 northeastern states (Ohio, West Virginia, and Virginia, up through Maine).

Hi ArtMAn

I keep getting "Currently Not Available" when I drill down for for any of the MapTech maps. Am I doing something wrong?

I'm seeing the same problem still on Monday morning. I just sent a note to the person listed as their tech contact in whois (the website didn't seem to have a useful email contact listed) and we'll see what happens.

 

-ArtMan-

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Some USGS monuments(mind you they are monuments not benchmarks, benchmarks are used for vertical and may or may not have an exact horizontal location associated with them) that were surveyed in the early days have a magnetic north location, not a true north or grid north horizontal location and have not been tied down to a GPS grid even though they have a lat and long in the USGS database...these were just a guess based on surveys of other monuments that were tied down. Even then some may be off due to the fact they were tied down before the advent of RTK surveying and are static locations.

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