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Details for Benchmark: AI4423

N 38° 53.333 W 077° 02.100 (NAD 83)

Altitude: 39.59

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

Location:
In DISTRICT OF COLUMBIA county, DC View Original Datasheet
Designation:
W M BASE SE
Marker Type:
NGS Benchmark
Setting:
setting not listed - see description
Stability:
May hold, but of type commonly subject to surface motion.

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With family visiting for a couple weeks, we have to show them some of the local sights. This was a great opportunity to tour the DC mall while secretly doing a little geocaching (and benchmarking) on the side. Easily found and in great condition.

[Photos:]
photoAI4423

Found in good shape while exploring Washington DC with TaGeez

Found it on an unseasonably warm evening in March on a trip to D.C. with the girlfriend. She had an all week conference, and I just geocached and hunted marks!

In DC for a conference and mapped out an ambitious agenda for finding virtual, earth, multis, puzzles and regular caches, as well as some bench marks!
Walked all around the monument!
TFTC< ponil

found wahile touring the area doing the Virtuals

Found it on my trip through Washington. Thanks for showing. :)

[Photos:]
photo12

Located this BM before going up to the top of the monument

[Photos:]
photoAI4423
SE corner of washington monument

Found while walking and geocaching the National Mall!

Found while walking the mall with friends from the UK.

[Photos:]
photoSE

Got the cover.

[Photos:]
photoai4423

I am unclear whether I observed this or not. The last update to the datasheet showed it not being recovered.

STATION RECOVERY (2012)

RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 2012 (DRD) NOT RECOVERED. NOTE-A NEW PROMENADE WAS LAYED AROUND THE MONUMENT

[Photos:]
photoAI4423 Benchmark
located in Washington, D.C.
photoAI4423 Benchmark Area
located in Washington, D.C.

Discovered while waiting for our tour inside

Logging some benchmarks after a long time on my list. Sorry for the late logging.

Found while on vacation

Found while caching.

Filling in some missing Benchmarks that I have discovered over the years.

Found this Benchmark while Geocaching in the area today. The cover is secured and cannot be opened to get an actual pic of the BM.

[Photos:]
photoBM AI4423

Recovered in good condition, in SE corner of Washington Monument. This access cover has a Torx screw in it, and cannot be opened. Any identifying marks on the cover have been removed, or it is a new cover.

[Photos:]
photoSE access cover

excellent

Mark itself is 6 inches below the surface, but found the little cover!

[Photos:]
photoCover
Pretty sure this is the right one, they kind of all look the same in my pictures.

Found it

Easy find on a quick walk around the base of the monument.

[Photos:]
photoDSC02100

Nice easy find. Found this benchmark whilst doing a rapid tourist trip around Washington.

[Photos:]
photoAI4423

A walk around Washington Monument to find all the BMs.

[Photos:]
photoAI4423

[white][/white]

Found it during lunchtime walk around monument.

[Photos:]
photoAI4423 Benchmark

Easy find

[Photos:]
photoAI4423

In DC for the week to attend a Geographic Conference, got out of class early so I decided to head to the mall for a few markers.
Got there at 4:30, National Christmas Tree lighting at 5:00 PM so I could not get a few I wanted.

[Photos:]
photoAI4423 Cover
photoAI4423 Location

Was here for a walk for Autism. Figured I would keep an eye out for some as I walk around the Mall.

Found while in D.C. with the family geocaching and vacationing!

Found this benchmark as well.

N 38° 53.373 W 077° 02.105

Found this one as well.

[Photos:]
photoAccess cover opened as well.

this was cool

Found the cap but there were a few too many people around to open.

Found the cover, and the park police wouldn't let me open it. They did promise the marks are still active.

so many in one area

[Photos:]
photoP5010017

Found this while visiting the Monument.

This one appears to still be covered - found WM CASEY SE (AJ1999) as described by seventhings in 2003.

The AJ1999 datasheet mentions in 2000 the promenade placed around the monument which would make WM BASE SE inaccessible - see below:

DESCRIBED BY NATIONAL GEODETIC SURVEY 2000 (DBC)
IN WASHINGTON D.C. AT THE WASHINGTON MONUMENT, THE MARK IS 1.3 FOOT (0.4 M) SOUTHEAST OF SOUTHEAST CORNER OF WASHINGTON MONUMENT, 28.5 FEET (8.7 M) SOUTH OF WM CASEY EAST, 25.6 FEET (7.8 M) SOUTH OF SOUTH EDGE OF EAST ENTRANCE. A PROMENADE WAS LAYED AROUND THE MONUMENT AND NGS LOGO CAP WITH A 1 FOOT (0.3 M) LONG PVC PIPE TO PROTECT BENCH MARK. THE LOGO CAP IS FLUSH WITH THE PROMENADE AND BENCH MARK IS 18 INCHES BELOW CAP.

AJ1999 is listed at waymarking.com - http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=aj1999

[Photos:]
photoWM CASEY NE (AJ1999) - area looking NE
Note - the collar was replaced several years ago & is now unstamped.

Found this one while walking around the mall on a surprisingly warn evening with some friends.

Found it, but the security guard would not let me lift the cover.

Found all the base Benchmarks, but not sure which ones are which now. I think I've got the in the right order, but...

[Photos:]
photoOne of the Washington Monument Base Benchmarks

Found with my family while strolling around the Washington Monument.
King Hubi

We made a lap around the monument this morning taking pics of benchmarks as we geocaching our way around the Mall.

Found this by accident!

Found while visiting the Mall.

Found on a virtual / benchmark run in the mall.

:}

Found while in touring the area today!

[Photos:]
photoAI4423

Saw during tour of the Washington Monument

Found this one while on vacation.
elawsan

After spending the morning touring the Capitol (and kicking ourselves for not bringing the BM data sheets) we headed out to do more 'touristy' stuff. We made a stop uip here to grab the benchmarks while wiating for our ride up the monument.

Found as described and recovered in good condition.

[Photos:]
photoclose up AI4423 - Washington DC

Found this easy enough, but failed to log the three others on the other corners. I got a little reprimand for opening the cover. Oops.

[Photos:]
photoThe cover
photoCover Opened

Found it today with all Stringfam. Screws are removed from covers. Always good to have kids who want to lift lids up. Very muddy at bottom. Could not see it but knoew it was there.

A really cool unexpected find. Photo:

[Photos:]
photoRight up against the Wa Monument

There is dirt in the hole, bring a flashlight to see down in.

Spotted this one today after ascending and descending the monument.

Ran over at lunch time to get these BM's.

Was at the monument this am and found the covers. Checked with onsite security if I could open the covers to photgraph the marks, but was denied permission. All I can say, is the covers are there and in good condition.

Found the access cover to this one while visiting the monument.

Still there.

Visiting WM

It's as close as you'll get.

[Photos:]
photoAI4423

The open lawn area surrounding the Washington Monument and significant portions of the north end of the ellipse are enclosed behind fencing for a landscaping, capital improvement project. (Not apparently, for security reasons.) WM tour ticket holders can only access the interior of the WM, not the outside and sidewalk surrounding. According to the National Park personnel, the lawn around the WM should be open for walking on by 4 July 2005. The sod was not even laid down when I observed the site. Sod usually needs 3 months without foot traffic. Your results may vary.

Found with Charlie.

The other end of the Monument.Peace Medal.

[Photos:]
photoWMSE
Peace Medal at Monument

Could not find this mark as it lies six inches below the concrete surface. However, I found W M CASEY SE and W M CASEY SW (Pids = AJ1999 and AJ1998, in the NGS database but not in the Geocaching database.
Revisited 12/16/05: WM BASE SE is still six inches below the surface and not visible in the vicinity. However, WM CASEY SE is a Waymark at:
http://www.waymarking.com/waymarks/WM501
WM CASEY SW is a Waymark at:
http://www.waymarking.com/waymarks/WM508

[This entry was edited by seventhings on Monday, September 24, 2007 at 11:22:29 AM.]

[Photos:]
photoW M CASEY SE
photoW M CASEY SW

Found this benchmark while visiting the Washington Monument.

I thought I found this also, until I looked a little closer. The monument at this point is NGS PID AJ1999; being WM Casey SE. I saw no sign of WM Base SE, it is supposedly 10 inches below the concrete.

[last edit: 4/26/2003 10:17:11 AM PST]

[Photos:]
photoWM CASEY SE

Tough find. Large stone pillar was in the way.

[Photos:]
photoRecovered

Odd how several have logged the Washington Memorial, but none of them logged these benchmarks right at the base. Guess I get to be the first.

[last edit: 3/15/2003 6:34:09 PM PST]

Documented History (by the NGS)

Unknown by RBNF (MONUMENTED)
11/10/1999 by NGS (GOOD)
DESCRIBED BY NATIONAL GEODETIC SURVEY 1999 (RWA) IN WASHINGTON DC, AT THE WASHINGTON MONUMENT, AT THE SOUTHEAST CORNER OF THE WASHINGTON MONUMENT, AN IRON BAR SET IN THE FOUNDATION OF THE MONUMENT WALL, 10 INCHES WEST OF EAST EDGE OF SOUTH SIDE, AND 6 INCHES BELOW CONCRETE SURFACE.

Control Text

  • The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
  • The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in April 2000. No vertical observational check was made to the station.
  • The geoid height was determined by GEOID99.
  • The dynamic height is computed by dividing the NAVD 88 geopotential number by the normal gravity value computed on the Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 degrees latitude (g = 980.6199 gals.).
  • The modeled gravity was interpolated from observed gravity values.

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