Jump to content
Sign in to follow this  
Followers 0
Bugsyboat

Does "BM" on a USGS topo map mean there is a Bench Mark there?

Recommended Posts

It means one was there at one time, but thats no guarantee its still there. Check the date on the map. If its old, consider whether or not the area has been developed. Concentrate on undeveloped properties. For example, a lot of the oldest ones I have found were set on church properties or municipal properties where they can easily remain undisturbed for decades, overseen and protected by those who maintain the properties. As a rule, the closer one is to a road, the less likely it is to survive.

Share this post


Link to post

I asked USGS and got the following reply:

Subj: Re: Benchmarks

Date: 8/28/2002 6:01:10 AM Mountain Daylight Time

From: ask@usgs.gov

To: FEBERT@AOL.COM

Sent from the Internet (Details)

 

 

August 28, 2002

From USGS:

 

The USGS is one of about 30 State and Federal agencies which might place

Benchmarks and other cadastral survey markers that may appear on the map.

Usually, there exists some sort of field monumentation according to the

practices of the agency which left the marker. If the agency was the USGS

or the National Geodetic Survey (formerly called USC&GS), then the measured

position would usually have been marked by a brass or aluminum circular

tablet about 4 inches in diameter and set in a concrete base. This might

have been deliberately buried or later covered by leaves, brush, etc. Some

of the markers have been destroyed by vandalizism or inadvertently covered

or plowed up by construction or other earth-movement activities. USGS

keeps paper records of the markers that its surveyors placed, and the

records may be obtained by specifying the current USGS quad map that covers

the area required. To the extent possible, USGS also records information

about destroyed or missing markers if the public informs us. Depending on

the amount of copying that is needed to fill a request, USGS may have to

charge for the copies. The National Geodetic Survey has its geodetic

control records online, and you can reach them at

- link to "data sheets".

 

In response, please use the e-mail address "Ask@USGS.gov".

Thank you,

Diane Brittle

USGS

Share this post


Link to post

quote:
Originally posted by Bugsyboat:

I've seen a few and was wondering if I go out there if I will find a Bench Mark. Thanks!


 

One more thing to keep in mind is that a benchmark that shows on a topo map may not be in the NGS database which is used here. If it isn't in the database, then there is not much that can be done other than write the USGS (or whichever agency placed the benchmark) if you are so inclined.

Share this post


Link to post

While at an undisclosed location in Maine, I went

to find the 'BM' that was listed on the topo map

of the area. Silly me. I thought I was looking for a standard disk. After a short time, of looking around the intersection of two rural roads, an elderly lady came out to see what I and my family was up to. When told about the benchmark, she asked if perhaps I was looking for the carved stone. What we found was an amazing stone something like a gravestone. It was a census marker. Every 10 years, some guy came through the area, took down the number of residents in the area, and carved the year into the stone to let other cencus taker know the are had already been done.

 

The 1/2 hour talking to this lady was wonderful. She recounted the time when some one "from away"

tried to steal the stone. That is why the location

must be left as undisclosed

Share this post


Link to post

quote:
Originally posted by pssweeney:

While at an undisclosed location in Maine, I went

to find the 'BM' that was listed on the topo map

of the area. Silly me. I thought I was looking for a standard disk. After a short time, of looking around the intersection of two rural roads, an elderly lady came out to see what I and my family was up to. When told about the benchmark, she asked if perhaps I was looking for the carved stone. What we found was an amazing stone something like a gravestone. It was a census marker. Every 10 years, some guy came through the area, took down the number of residents in the area, and carved the year into the stone to let other cencus taker know the are had already been done.

 

The 1/2 hour talking to this lady was wonderful. She recounted the time when some one "from away"

tried to steal the stone. That is why the location

must be left as undisclosed


 

Maine....hmmm?! Did the old lady say what happened to someone "from away"? I'll bet Stephen King knows what probably happened to this someone "from away". You were lucky, I suggest that you never return to that stone.

Share this post


Link to post

I found 4 benchmarks this morning, all placed in the same year. 3 I found on the massillon quad, the other one I did not see. Any reason why this would happen? Anyone else ever run into this?

 

Jim

 

Sommes-nous perdus encore?

Share this post


Link to post

The mapping was done by the USGS and little if any effort was made to coordinate with the NGS. The USGS generally showed only those markers that they happened to use or find during their work. Some NGS markers are part of the USGS network, others are not.

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  
Followers 0

×
×
  • Create New...