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Details for Benchmark: TZ4834

N 24° 37.778 W 082° 52.371 (NAD 83)

Altitude: 44

Coordinates may not be exact. Altitude is VERTCON and location is ADJUSTED. (more info)

Location:
In MONROE county, FL View Original Datasheet
Designation:
FORT
Marker Type:
survey disk
Setting:
footings/foundation walls of small/medium structures
Stability:
Probably hold position/elevation well.

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Found it 3/2/2019 at 1:05p.

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photoTZ4834
TZ4834 FORT

Found awhile ago.

Found while visiting here - very cool place!

Found this during our visit to Dry Tortugas and Fort Jefferson. What a great time we had. Caching with the Love of my Life making great memories to last a lifetime and beyond.

Found while visiting the lighthouse out on tortugas.

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photoimage

Found this while touring the fort.

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photobenchmark
Dry Tortugas

Easy to find if you survive the boattrip to the island

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photoBenchmark

Found this while visiting Dry Tortugas

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photoDry Tortugas

touring the fort and came across this benchmark

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photobench

We found it during our holidays in Florida.
Very nice place here.

Thank you and greetings from Germany. :)

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photosurvey mark

visited Fort Jefferson while on vacation, several benchmarks exist here, not 100% I found the exact one described

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photoimage
photoimage
photoimage

FYI....Found some Army Corps of Engr's Survey Markers on the Moat Walk. -hfogg(VA)

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photoSurveyMark_DryTortugas

One of the best benchmarks I have found. Benchmark is on top of the fort.

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photoFORT Benchmark
Yes there is a Benchmark here

Found this one on walk back from snorkeling. I found the virtual while at the fort but did not even think about benchmarks. So this was a nice surprise while walking the moat wall.

Found this benchmarch while walking around the moat of Ft. Jefferson. Awesome to come across this.

Found this while on a morning walk around Ft. Jefferson. My son's Boy Scout Troop camped at the Ft for 3 nights. It was an awesome experience for me and my son.

[Photos:]
photoFt Jefferson

Did not locate.

Best benchmark I didn't find!!! The fort and view is gorgeous. Talked to the park rangers and they knew of the survey disk but stated there was some work done in that area. It may be buried under the sand and local vegetation. Didn't want to disturb the spot!

Found this on a trip to Fort Jefferson. This is a beautiful location I reccomend everyone see this if possible.

Documented History (by the NGS)

01/01/1992 by NOS (MONUMENTED)
DESCRIBED BY NATIONAL OCEAN SERVICE 1992 THE STATION IS LOCATED ON GARDEN KEY IN THE DRY TORTUGAS ON TOP OF FORT JEFFERSON. TO REACH THE STATION FROM KEY WEST, PROCEED WEST BY BOAT FOR APPROXIMATELY 70 MILES TO GARDEN KEY AND FORT JEFFERSON NATIONAL MONUMENT. PROCEED FROM THE DOCK ON FOOT THROUGH THE MAIN ENTRANCE AND ACROSS THE PARADE GROUNDS TO THE NORTHERNMOST STAIRWAY LEADING TO THE TOP OF THE FORT. CONTINUE UP THE STAIRWAY TO THE TOP OF THE FORT AND PROCEED ESE ALONG THE WALL TO THE FIRST RAMPART AND TO THE STATION ON TOP OF THE RAMPART. THE STATION IS A STANDARD NOS BRONZE DISK STAMPED FORT 1991 AND SET INTO A DRILL HOLE IN THE CONCRETE ON THE TOP OF THE RAMPART. THE DISK IS SET IN THE CENTER OF THE HIGHEST PART OF THE RAMPART.
12/04/1991 by (GOOD)
RECOVERED 1991 RECOVERED IN GOOD CONDITION.

Control Text

  • The horizontal coordinates were established by GPS observations and adjusted by the National Geodetic Survey in September 1992.
  • The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.)
  • The X, Y, and Z were computed from the position and the ellipsoidal ht.
  • The Laplace correction was computed from DEFLEC99 derived deflections.
  • The ellipsoidal height was determined by GPS observations and is referenced to NAD 83.
  • The geoid height was determined by GEOID99.

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