BM Not In NGS Database?

[+LSUMonica]

I was in Phoenix, Arizona last month for a spur of the moment geocaching/benchmark hunting trip. In preparation for my trip I downloaded the yearly archived data sheet sets for Maricopa County and imported them into my benchmarks database in GSAK using BMGPX.

 

So while out and about I decided to look for RV 74 (DV0220) and 1112.49 (DV0219) which were fairly close to the road and not on private property.

 

For DV0220 I found the railroad abutment as described but no benchmark, but I did find this nearby...

 

 

on the curb of the road...

 

 

Question 1: So I realize this is not RV 74 (DV0220) but is it a benchmark that should be added to Waymarking.com

 

So I went across the street to find DV0219 and found a benchmark "AT A HIGHWAY BRIDGE OVER AN IRRIGATION CANAL, IN THE TOP OF THE SOUTHEAST CONCRETE ABUTMENT, AND 0.9 FOOT WEST OF THE EAST END. " but it has different stamping of 1114.30 but placed by the Arizona Highway Department...

 

 

on a concrete abutment...

 

 

But this marking in not in the NGS database. The approximate location according to my track logs is: N33 29.353 W112 07.639

 

Question 2: Is this a benchmark not in the NGS database or what???

 

Thanks for the help!

 

LSUMonica

[mloser]

Question 0: You didn't ask about the unfound benchmark on the railroad abutment, but I think you may have been looking for the wrong thing. Even though the datasheet says the mark is a "survey disk" I am thinking that it may be a rivet, based on the name of RV 74 and the nearby DV0541, which has a marker type of RIVET. From my memory all marks with RV in the designation have been rivets. That isn't to say they ALL are, but I would certainly entertain the possibility that you saw it and didn't recognize it because you weren't expecting it. KW1496 is an example of a rivet I found recently. Do you remember seeing anything like that on the bridge.

 

Question 1: That mark is probably not in the NGS database (I didn't search as you already said you did). There are probably nearly as many benchmarks NOT in the database as are in it. That means that it was not submitted to the NGS for inclusion, or possibly that it was submitted but not up the standards of the NGS. You needn't log it anywhere if you don't want.

 

Question 2: I think that is a reset mark in a newer bridge. The described mark was last recovered in 1959 and I think I see a date of 1964 on the one in your pic. This makes me think the bridge was replaced in 1964. The stamping on the disk is the elevation and chances are that changed when the bridge was rebuilt.

[+Shorelander]

Question 1: So I realize this is not RV 74 (DV0220) but is it a benchmark that should be added to Waymarking.com

If you're asking whether this is the kind of benchmark that the US Recovered Benchmarks category collects, the answer is yes - but as mloser said, there's no obligation to waymark it.

[treker239]

NGS doesnt list local BM from the states or local municipalities in most areas you have many different BM systems

 

 

 

I was in Phoenix, Arizona last month for a spur of the moment geocaching/benchmark hunting trip. In preparation for my trip I downloaded the yearly archived data sheet sets for Maricopa County and imported them into my benchmarks database in GSAK using BMGPX.

 

So while out and about I decided to look for RV 74 (DV0220) and 1112.49 (DV0219) which were fairly close to the road and not on private property.

 

For DV0220 I found the railroad abutment as described but no benchmark, but I did find this nearby...

 

 

on the curb of the road...

 

 

Question 1: So I realize this is not RV 74 (DV0220) but is it a benchmark that should be added to Waymarking.com

 

So I went across the street to find DV0219 and found a benchmark "AT A HIGHWAY BRIDGE OVER AN IRRIGATION CANAL, IN THE TOP OF THE SOUTHEAST CONCRETE ABUTMENT, AND 0.9 FOOT WEST OF THE EAST END. " but it has different stamping of 1114.30 but placed by the Arizona Highway Department...

 

 

on a concrete abutment...

 

 

But this marking in not in the NGS database. The approximate location according to my track logs is: N33 29.353 W112 07.639

 

Question 2: Is this a benchmark not in the NGS database or what???

 

Thanks for the help!

 

LSUMonica

[+Klemmer]

NGS doesnt list local BM from the states or local municipalities in most areas you have many different BM systems

I beg to differ, treker239. In my area, there are MANY benchmarks placed by state, county and other local agencies, which are listed in the NGS database. They might even be the majority in SoCal. I believe it all depends on whether the state and local survey agencies wanted to go through the required efforts to get the accuracy and submit them to the NGS. What you say may be true in your area, but not everywhere in the US.

 

For a very nice collection (still being aded to all the time!) of the agencies that have placed "benchmarks" of various types, see Buckner's Agency List.