What Have I Found?

[+BobboTeam]

A friend of mine was up in northern Minnesota, near the Canadian border in Voyageur's National Park. On a very small island, between Namakan Island and Twin Alligator Island he founds this mark, but I do not find it in the Groundspeak database of USGS benchmarks. (It is at or near N 48°26'36"N 92°41'49"W)

 

Can anyone identify it?

 

 

Thanks

[+Kewaneh & Shark]

You've found a Public Land Survey System (PLSS) Section Corner. The PLSS is a grid system comprised of townships (6 x 6 miles = 36 square miles) and sections within the townships (1 square mile). As a general rule, the corners of each section and township was monumented. Many of those monuments were brass caps (which look like benchmarks) and labeled as GLO Survey monuments. (Other monuments used included, among other things, stone monuments, stone piles [cairns], pits & mounds, and wood posts.)

 

Other threads on this topic can be found HERE & HERE, and THIS POST has links to additional threads too.

 

Hope this helps!

 

- Kewaneh

Edited August 1, 2006 by Kewaneh & Shark

[+BobboTeam]

You've found a Public Land Survey System (PLSS) Section Corner. ... Hope this helps!

 

It helps immensely, thanks. I'll keep my eyes open for those, as well. I'm mildly disappointed about not being able to add the photo to the database, but the ed-ja-macation you gave makes up for that.

[+BuckBrooke]

As a quick note, Bobbo, the Geocaching database is a copy of the NGS' database, not the USGS. This may seem pedantic, but the USGS does not have an online database. 99%+ of the USGS disks have not been added to the NGS database, which is comprised mostly of US Coast & Geodetic Survey (NGS precursor) and NGS disks, with a lot of other national, state and local agencies.

[tosborn]

I would not have expected that a monument would have been placed on the small unnamed island between Namakan and Twin Alligator Islands. Normally, in the Public Land Survey System 8 corners were marked for each section (e.g. the 4 main corners SE, SW, NE, and NW, and 4 so-called quarter-corners typically half-way between the main corners.) The monument your friend found is only about a quarter-mile East of the SW corner of Section 19 located on Namakan Island, making it a 1/16th corner. It would have been interesting being the Deputy Surveyor contracted to run the interior lines of that Township!

 

It appears that "A M C" is stamped toward the top of the monument. I don't know what that would be other than the initials of the surveyor who set the monument.

 

P.S. It looks like the South Quarter Corner of Section 19 would be just on the extreme Eastern shore of Twin Alligator. I don't suspose your friend looked there?

[Bill93]

Meander Corner? If this is along a lake it would make sense, but I'm not sure why A.M.C. and why not corner numbers along the meander line.

[+GEO*Trailblazer 1]

Meander Corner? If this is along a lake it would make sense, but I'm not sure why A.M.C. and why not corner numbers along the meander line.

 

Alternate Meandor Corner?

[+jwahl]

Auxiliary Meander Corner: These are set on small islands when they are surveyed. The BLM Manual of Surveying Instructions 1973 Chapter 3 Section 122 states in part:

 

Any township boundary or section line which will intersect an island is extended as nearly in accordance with the plan of regular surveys as conditions permit, and the usual township, section, quarter-section, and meander corners are established on the island. If an island falls in two sections only, the line between the sections should be established in its proper theoretical position based upon suitable sights and calculations. If an island falls entirely in one section, and is large enough to be subdivided (over 50 acres in area), a suitable sight or calculation is made to locate on the margin of the island an intersection with the theoretical position of any suitable subdivision-of-section line. At the point thus determined a "special meander corner" is established. In the case of an island falling entirely in one section and too small to be subdivided, an "auxiliary meander corner" is established at any suitable point on its margin, which is connected with any regular corner on the mainland. The direct course and length of the connecting line is given in the field notes and shown on the plat.

 

Minnesota GLO plats are online. Here are two which cover islands in that township

 

Plat 1

 

Another

 

To download higher res versions

 

-jlw

 

Meander Corner? If this is along a lake it would make sense, but I'm not sure why A.M.C. and why not corner numbers along the meander line.

 

Alternate Meandor Corner?

Edited August 2, 2006 by jwahl

[tosborn]

jlw:

 

Thanks for the clarification. The links you provided point to plats for T69N R19W, but the monument is for Sec 19, T69N R18W. Here is a link to the low res plat that shows Sec 19, T69N R18W:

 

http://www.lmic.state.mn.us/surveydata/stl...69r18w4fi01.pdf

 

The area of interest in on the left of the plat, a little below the middle of the sheet.

 

And here is the link to the high resolution zipped pdf of the same plat:

 

http://www.lmic.state.mn.us/surveydata/stl...69r18w4fi01.zip

Edited August 2, 2006 by tosborn

[+jwahl]

Oops, Sorry for the mistake...

 

Here is the plat with your island and AMC

 

More Islands

 

jlw:

 

Thanks for the clarification. The links you provided point to plats for T69N R19W, but the monument is for Sec 19, T69N R18W. Here is a link to the low res plat that shows Sec 19, T69N R18W:

 

http://www.lmic.state.mn.us/surveydata/stl...69r18w4fi01.pdf

 

The area of interest in on the left of the plat, a little below the middle of the sheet.

 

And here is the link to the high resolution zipped pdf of the same plat:

 

http://www.lmic.state.mn.us/surveydata/stl...69r18w4fi01.zip