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Details for Benchmark: GR0585

N 36° 00.967 W 114° 44.217 (NAD 83)

Altitude: 1234.91

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

In CLARK county, NV View Original Datasheet
Marker Type:
triangulation station disk
light structures
Mark of questionable or unknown stability.

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While walking over hoover dam i found many of the benchmarks while not even searching for them.
Now i try to ide tify them by designation and photos to log them in the system as well.
I cannot see a designation on my bm. But log photos fit to my photo

Greetings from germany

Since I was traveling from California to Utah alone today, I decided to add a number of hours to the trip and visit the dam. I enjoyed it and I was able to find a few geocaches and benchmarks along the way.

You can't make out the 'B' or the date anymore, but the description matches very well.

photoClose up

Touring the bridge and dam today and then using to find a ton of marks on the dam. I wish I could have had a few more and I would have pulled off a really easy 25 BM day! Oh well.

This appears to be a duplicate of GR1850. This one barely has a single line stamped into it, but nothing you can recognize as a B. However, the location is dead on for this nearly blank mark. You can also compare old photos and see where the B used to be and the parts of the 1935 that are still barely visible.

photoB Up Close
photoB Setting View
This is standing east of Q 135 looking west towards the center of the dam with B in the middle of the dam and labeled in my photo.

found it while on vacation.

Visited by Tour HQ2018
Greetings Thomas from germany


Found while visiting the site.

photoBM at site

I was in Vegas for a long weekend and spent the morning at Hoover Dam, grabbing the new virtual and searching for benchmarks, before heading to the airport for my redeye home. I was here five years ago and noticed they are all over the place, so why not log them. Spotted this one well worn.

The designation has completely worn away from this mark but I think I found the right one. It matches the 2014 recovery note about the stamp being worn. It is located on the upstream sidewalk of dam next to the NV/AZ border plaque.


With Jeepers-GasFree

Joyful Noise and I were on Vacation from Michigan (Brrr. and double Brrr). We took a break from finding geocaches to find some benchmarks instead.

We came for the Dam Tour, but found a bunch of Benchmarks too. Easy to find, hard to figure out which is which.

photoClose-up View of GR0585
photoStep-Back view of Gr0585

found it. The 'B' is completely worn away now.


Mit Stage_Worm diesen Benchmark gesucht und gefunden.....

Auch diesen Benchmark konnten wir gleich entdecken !!

Also found this one on my walk on the dam.

Found while at the dam.

Cool Location with a lot of Benchmarks in this area.

So many Benchmarks here.

OMG! Seems as the whole Hoover Dam is covered with Benchmarks. I found quite a lot, but not sure if I found all of them. Many of them are located just within a couple of feet.

Found in good condition. Looks like traffic has had an effect on it, but otherwise, easy to find.


Found while on vacation

Wasn't looking for them but just happened to see a few while visiting Hoover Dam.

Found many more on the dam but not all of them are on the list. This one I had to do a little digging to find the correct listing but it matches the other photos on the page.

photo'B' on the dam

Found in good condition


Fount it on my trip to Hoover Dam


Found it during our western migration to California from Florida.

Found while on a visit to the area.


Recovered In good condition.


Found while exploring dam

Walking Hoover Dam, benchmark #3 .

photoBenchmark "GR0585"

Found the disk while walking around the dam


Found this while walking the dam.

Found this while walking the dam.

Walked the entire length of the dam both sides and photographed all the benchmarks we could find. All we found were in good shape.

Found it during my weekend in Las Vegas, Hoover Dam and Death Valley.

photoLogproof Benchmark GR0585

I've found a few benchmarks before, but this is the first one I've ever logged!

Saw this benchmark while visiting the Hoover Dam.

Found walking on Hoover Dam

photoGR0585 B

Finally got to walk the Rail road tunnel trail with sassy13, rrgeo & 50+. We ended up doing 10 miles. Glad we started early for it got really hot. Didn't expect to find any GeoCaches. And these were an added bonus.

Accomplished the Historical rail road tunnel trail today with sassy13, ejworth and 50+. It turned out to be a 10 mile hike. Thank goodness it's only February. Thanks.

Recovered in heavily worn, unreadable condition while visiting the Hoover Dam.

photoB - Hoover Dam

Got another

Found it...

Found another

Great dam benchmark!

(Translated with Google):
Some geocachers were planning a trip to the US for ET Power Trail and various old geocaches. I was asked if I would like to join the tour and I had! On 10/01/2015 our (Butjer, Tudor99 and ropno) personal Roadtrip 2015 began.

We started in Las Vegas with 93°F hot humid summer weather, drove to the Hoover Dam and explored the "Strip" and many great Virtual Caches. On the way to "Keyhole Canyon Cache" on the first day we were very glad we rented a Chevy and not a Van, because offroad is not precisely comparable to big city streets!

At one of the selected old caches for our trip we found this bench mark. It´s my first one!
The simple was to make a photo of it (10/02/2015). The difficult was to find the page where I can log the bench mark. But today I have hidden access finally found! Yeah!

After a few days we went into the desert for Extraterrestrial Highway with its many, many (2400!) ET caches and brought the rain. The temperature dropped through the storm clouds on homelike 65°F, we had no dust on the "dirt roads", no flooded roads as it "poured out all buckets" rarely about us, the clouds mostly very fixed in the near mountains. We didn´t get a sunburn and needed less water than planned to drink. We saw a lot of cattle, horses, antelopes, a coyote, rabbits, many birds, bugs and insects, as well as beautiful areas and landscapes, yellow flowering shrubs and more cars and quads than expected, but fortunately no rattlesnake or scorpions. On the fourth day in Nevada desert the sun came through and we saw still the expected "desert feel".

The second week our tour continued north to the oldest caches over Lake Tahoe, Eureka, Crescent City to the Pacific coast (50°F, fog) and on about Oregon City to Seattle (63°F, sun) to Groundspeak HQ and there was even time for trip to Utah, Idaho, Montana and a day trip by catamaran to British Columbia in Canada.

After 11441 mi by airplane, 3538 mi by car, 175 mi by ship and approximately 72 mi on foot walk unfortunately and we had to go home on 10/16/2015. But the idea for the next US tour is already on the horizon...

Best regards from Germany

photoVisited Hoover Dam and GR0585 - 02.10.2015

We Tudor99, ropno and i found this one during our trip to Hoover Dam.


Nice found, during visit on Hoover-Dam

Found this while visiting the Hoover Dam with family.

photoBenchmark - Triangulation Disc B - Hoover Dam

Found while visiting the dam.

I found this one while visiting the Hoover Dam. The disk has been polished way too many times and the center and some of the edge characters are fading away.

This one is considerable more worn in the middle than the others.

Discovered this one while visiting the dam.

Discovered this one while visiting the dam.

Same mark as GR1850. Found while walking the dam today.


man are there a few benchmarks on this dam!!!

Found while exploring the dam with the magtfplanner crew !

photoB Disc
photoB Disc Area
Under the State Line Plaque. As you can see, clearly on the Nevada Side ;)

Found while visiting Hoover Dam

photoMiddle of Dam

Found with spooky_luke

Found whilst exploring Hoover Dam


Found at Hoover dam.

photoGR0585 B Hoover Dam

Found this benchmark along with many others while walking across the Hoover Dam. I'm pretty sure this is the right one. I believe the B has been worn off, but this was in the correct location.

photoB Closeup

Found it while hiking and visiting Hoover Dam with the family.

Too many benchmarks not enough time!!! And too hot!

Hab Dich gesehen!!


Visiting from S. Florida and checking out all the benchmarks on the Hoover Dam. Pretty cool!

photoGR0585 Gungadoy

Spotted this one while touring the Dam today.

Found whilst visiting the U.S. together with Turako and Silas07.

Discovered while taking a breack while working on the E.T. trail in December

Found while visiting the dam.

Found while at Hoover dam.

There are so many benchmarks at Hoover Dam! Found it!

Found it today at 11:05a


Everywhere we looked we saw a BM, this one we had to wait for others to move so we could look down again and take a picture. Gee I wonder what others were thinking when we bent down to take a pic of the walkway! Didn't look back to see if anyone else knelt down to look at what we just did!

photoHey look out we want to get this BM in the middle

Taking a pic on the bridge and stepped on this benchmark.

We stopped at the Hoover Dam as part of our 6,000 mile road trip. We couldn't resist getting 10+ benchmarks in just a few minutes! I found this with my crew - Universal Warrior, Scooby boy, and Y dance girl!


Found while touring Hoover Dam with my hubby - was thrilled to find lots of benchmarks along the walk across the top of the Dam.


Found several benchmarks while on vacation. Great location!

Found while visiting the dam

photoB Hoover Dam NV,AZ state line

Found while doing some waymarking and geocaching at the Hoover Dam.

On our trip to the Hoover Dam we spotted a number of benchmarks, which we photographed. I should have taken a GPS reading, but I figured the photo would be good enough. It did take some work to track down which benchmark it was.

photoHoover Dam Triangulation Mark

Photo prise lors d'un voyage en compagnie de 'Le J', eMCé et MaitreJack.

Dans la région pour 17 jours, nous en profitons pour visiter le maximum de caches, de Benchmarks et de Waymarks.

C'est en fouillant dans nos photos que j'ai constaté que nous avions visité ce Benchmark.

merci pour ce benchmark.

Baie Comeau, Quebec Canada


Photo prise lors d'un voyage en compagnie de 'Le J', eMCé et ORDIMIC. Nous sommes partis du Québec, Canada le 25 mars 2013. Aujourd'hui, 9 avril, nous visitons Las Végas et Hoover Dam principalement par ses caches virtuelles et des waymarks. Merci pour le benchmark.

Picture taken during a trip in the company of 'Le J', eMCé and ORDIMIC. We left Quebec, Canada March 25, 2013. Today april 9, we visit Las Vegas and et Hoover Dam primarily by its virtual caches and waymarks. Thank you for the benchmark.

MaitreJack, Rimouski, Québec, Canada


We were suprised with how many marks there were here.

Me too, me too...

Given the coordinates, and other finder's photos, I believe we also found this mark. However, the inscription under the word "MARK" does not look like part of a B to me.

Making a Benchmarking trek back and forth across the dam. Snapped a pic


Found this by accident while on vacation at Las Vegas.


Found while sightseeing after doing some amazing Zip Lining in Boulder Canyon. Lots of benchmarks in this area!

During our ET & Route 66 trip we also did some sightseeing, we've discovered a lot of Benchmarks, this was one of them.

While doing the E.T.trail, Route 66 and some sightseeing, we (fscheerhoorn, eikenhofjes, M.I.Casa and hoekraam) have seen a lot of Benchmarks, this was one of them.
Greetings from The Netherlands (NL)

Team M.I.Casa

While doing the E.T.trail, Route 66 and some sightseeing, we (fscheerhoorn, eikenhofjes, M.I.Casa and hoekraam) have seen a lot of Benchmarks, this was one of them.
Greetings from The Netherlands (NL)

On my hollyday we found a lot of caches
Thanks for the benchmark

From [orange]Holland[/orange]

On our trip to the Hoover Dam we also saw this disk.

photo2012-09-18 14.35.41

Found while taking photos of the dam


found in good condition


Found at the AZ/NV border on the Hoover Dam. The designation has been rubbed off.

Designation - B

Enjoyed touring the dam.

I walked across the top of the dam taking photos of all of the benchmarks I could find by sight in the twilight. Thanks!


We just finished the the Dam tour and I noticed this benchmark.

Seen whilst visiting the Hoover Dam.

Found while visiting the Dam with friends. We were amazed to see so many benchmarks.

What an amazing spectacle! This was our first major stop while visiting Vegas.

The Zombie Horde was enjoying the view and the history.

Found it when we visited Hoover Dam!

Definitely worn down from the tourist travel, but still recognizable.

photoTriangulation Mark B

Found this one at my holiday

The Netherlands

During our ET & Route 66 trip we also did some sightseeing, we've discovered a lot of Benchmarks, this was one of them.

Greetings from [orange]The Netherlands![/orange]


[blue]Happy caching![/blue]

Enjoyed my walk on Hoover dam today grabbing up some cool benchmarks. Found this benchmark in good condition. Looks like the "B" has been rubbed off for being polished. Either by workers or just people walking along. Although it looks like they all have been polished at some point and time. #82

photoGR0585 Stamped "B" monumented 1935
Close up of bench mark. "B" is no longer visable
photoGR0585 Stamped "B" monumented 1935
Plaque just above bench mark on Hoover dam
photoGR0585 Stamped "B" monumented 1935
Bench Mark Location looking North

Found while walking around the Hoover Dam. Very shiny in the sunlight! Looks like it gets polished!

Found with pritzen while checking out the Dam


Found this benchmark together with Silas07 and Turako during our three-week-trip in the U.S.

Found during the Hoover Dam tour while on vacation with the Amazon. Apparently there are 100's of these here. We only took pictures of 6 of them so that's all we're logging. We're still pretty new to logging benchmarks.

Out on the Dam and found this disk.


[red]Found it on my way to Vegas! Visiting from Alabama![/red]

Found it while caching California, Arizona, Nevada and Utah with the Desert Seven (FE, Mobcacher, Lindbergh31, WadeMercer,ZeppoCruz, PrairieEarth and SkooterColumbo)

Found it while caching California, Arizona, Nevada and Utah with the Desert Seven (FE, Mobcacher, Lindbergh31, WadeMercer,ZeppoCruz, PrairieEarth and SkooterColumbo)

One of many benchmarks that I found on the Hoover Dam. This one is right on the Arizona/Nevada border.


While in Vegas, my wife and I rented a car and drove to the dam. I made her take pictures of every benchmark nearby. I'll post them when she decides to upload them!

Found while walking Hoover Dam.


Found along with 5cent on the damn Dam! :c)


While visiting Hoover Damm

Found it while on the Damm

Found this one quite by accident. Wish I had been more prepared and known there were so many around.

Found it with friends from Pennsylvania.

Saw it at the dam.

One of many benchmarks at Hoover Dam. Great place to hunt for BM's. Hard to figure which one this was. Used other photos to determine it.


Had a little difficulty identifying this disk as it appears to be void of a character stamp. Triangulation stamp clearly identifiable.

a very impressive construction - found the benchmark while visiting the hoover dam and on our powercachingtour through california, nevada and arizona - best regards from austria - kiwilex

Found on the way to LV

Found while touring the Hoover Dam


I am loving the dam but that bridge built above it is very beautiful !

Another dam benchmark

Found as a team member of the “Space Cowboys”. Re-logging under my own account.

Found while walking across the Dam.
One Bavarian Space Cowboy

N 36° 00.976 W 114° 44.233

Found walking on top of the Dam. Near the State Line plaque.


No caches, so benchmarking. Walking the dam.

Dam benchmark

Was headed to St. George from Phoenix and stopped at the dam!

Found during Las Vegas trip and visit to Hoover Dam


Found while visiting Hoover Dam with the family today. Took a picture, but no need to clog up the servers with more pictures of the same thing.

found along the way to grand canyon


Found while visiting the Hoover Dam with my daughter and DRTrack.

Found while enjoying a visit to the Hoover Dam.

photoGR0585 "Triangulation B" Close-up

Found While Visiting Dam

Yep its there... It's not going anywhere anytime soon!


Found as described.


Found this one at the Hoover Dam. Landnavmaster

photoHoover Dam Triangle B
Hoover Dam Triangle B
photoHoover Dam Center of Dam
Hoover Dam Center of Dam

elevation 1183 ft. Found in good condtition as described. As reported by others, the mark has been rubbed pretty clean off but the B is still appearant. I only am logging this because of some experienced finders.

photoGR0585 B_01
photoGR0585 B_02

Found while visiting the dam.


Found while I was looking around at Hoover Dam.

photoGR0585 marker

Found it on a great day benchmarking on Hoover Dam


found during visit an dam, when pic required I can post it

I have visited Hoover Dam many times, but it was before I knew about benchmarks and geocaching. I came here to get some pictures of the new bridge under construction. Wow! Finding a bunch of National Geodetic Survey markers on the dam was a bonus.

Found walking across the dam (me--not it)

Found this benchmark touring Hoover Dam.

Found on our way to Quartzsite, AZ.

found while visiting the dam

phototriangulation disk

Found on a trip to the Dam


Right in the middle! Fiddlefiend , the Pharmacacher and I were out for a nice day. Mandolinman

nice to find so many marks

nice to find so many marks

nice to find so many

One of eight today in the area. I have never had a chance to find this many right in the same area.

Found while visiting the dam with 007. Wonderful view!!

Found on a family vacation. It was REALLY hot today!

One of several benchmarks found while playing tourist at the Dam.

Found this benchmark walking across the Hoover Dam for a cache.

Easy find in the sidewalk along with many others.
It seems likely that GR0585 and GR1850 are the same marker.

photoTriangulation Station B

Found it near the Nevada/Arizona dividing line of the dam on the sidewalk on the north side.

photoBenchmark B, Hoover Dam

Recovered as described.

photoGR0585 Disk on Hoover Dam
photoGR0585 Maxi Closeup

Found this after the tour of the Dam.

Found after tour of dam

We took the full Hoover Dam Tour which ends on top of the dam right near this marker. We really enjoyed visiting this great dam. We didn't get a closeup of the marker; just the long shot.
Peter and Gloria
Winnipeg Manitoba Canada

photoC:\Documents and Settings\Peter McLure\My Document

Went to Hoover Dam on a cold and windy Christmas day. Lots of people there even though the visitor center was closed.

It seems likely that GR0585 and GR1850 are the same marker.

photoGR0585 or GR1850
photoGR0585 or GR1850 location

Yep, still there.

Saw these as we walked across the dam. Thanx!

Found this one on our way back from Vegas.

Awesome place in America.

Found it while visiting the dam.

Found the 3 on the top near the border between AZ and NV forgot about benchmarks till I saw on the top of the dam. Took a picture for me to log when I got home.

Found nineteen benchmarks on and around the dam today.

Found amongst a treasure-trove of benchmarks in this area!

Mark getting a little worn from foot traffic.

Found after touring the dam.

photoB Disc - Hoover Dam, NV.JPG

Great day for a visit to hoover dam found this benchmark along with a few others.


Found after Hoover Dam tour. Wasn't even looking for it.


Found it while on vacation to the see the Dam!!

Found this while on vacation.

photoVacation 2006 359.jpg

First of 4 Benchmarks found on Hoover Dam. This is worn off.

photo1st of 4 Benchmarks found on Hoover Dam

Mark and Wendy from Team Fuji found this on the walk across the Hoover Dam

photoDisk as seen from the top
Mark and Wendy from Team Fuji found this on the walk across the Hoover Dam

The B is almost completely worn off now.

photoB BM
photoBM B Location

Found in poor condition. The B is barely legible from foot traffic wear.


No gps in picture. Lots of benchmarks on the Hoover Dam.

photoThe BM

This was one of several benchmarks that I found while walking over Hoover Dam this evening.

photoBenchmark with GPSr

This appears to be another duplicate listing as [url=]GR1850[/URL], but we located it today while hunting them out.

I was shocked at how many people will stop to hear about what benchmarks are.

photoB marker + GPS
B Needs restamped

With Family at Hoover! Same as PID GR1850

[This entry was edited by tissa1020 on Tuesday, November 22, 2005 at 2:08:14 PM.]

photoMarker "B"
People walk over it and don't even NOTICE!

Found this one, along with all the others around here. But the photo I took didn't come out
Cheers M+S

[This entry was edited by the.pud on Thursday, October 20, 2005 at 5:02:06 PM.]

12:00 PM Found it.


The only problem here is keeping track of all the benchmarks around here.

Found as described and at handheld cooridnates N36-00.977 W114-44.234. This is also PID = GR1850.

photoGR0585 and GR1850
photoGR0585 and GR1850 at Hoover Dam, NV


Recovered in good condition. Can see faint B on mark.


photoB -- CLARK county, NV

Found this one with no trouble - the picture isn't very good though.

photoArizona Nevada State Line BM.JPG

Found as described.

Found it!

N 36° 00.979 W 114° 44.234

Found as described, midway between the elevator towers, located on the upstream side of the dam on the sidewalk, just below a plaque marking the border between Nevada and Arizona.

photoB triangulation station disk

Found with Skydive121

One of a bazillion benchmarks found here on Friday the 13th. I guess it made paying for parking worth it. Found with Zues_4.

found it..


Recovered in fair condition


Only I could go out of town with out the GPS and a list of caches to visit. Never, at least the benchmarks are here. I do beleive this is number 100.

Found it in OK Condition

Found this one along with 12 others while touring the dam. I wan't even planning on doing any geocaching or benchmark hunting while on this vacation, but I couldn't pass up the opportunity. As I expected, they are well documented and photographed, so I won't add yet another picture to the database.

Found it while walking across the dam.

Still there.


Located as described in good condition.

Recovered in good condition...

N 36° 00.977 W 114° 44.240

Benchmark recovered as described, in fair condition. Benchmark is well worn, and the brass cap is very shiny.

I am guessing that this benchmark (PID# GR0585) is the same benchmark as PID# GR1850.

photoBenchmark B w/GPSr
photoBenchmark B. Very Worn.
photoNorth at Benchmark B, Right on the Nevada/Arizona Border
photoThe Plaque at the State Border

No kidding about trying to figure out which one is which. Many feet took a good toll on most behcnmarks in the area.

photoPeripatetic Piglet

Realized the hardest thing about recovering benchmarks around the Hoover Dam is not finding them, but trying to decipher which ones you found. The stamps are worn due to heavy foot traffic.


Great place to visit and a chance to find a few benchmarks.

Recovered this benchmark in April of 2001 While visiting Hoover Dam following the National Association of Broadcasters convention in Las Vegas. I highly recommend the hard hat tour.


Documented History (by the NGS)

01/01/1935 by CGS (MONUMENTED)
01/01/1950 by NGS (GOOD)
01/01/1963 by NGS (GOOD)
01/01/1981 by NGS (GOOD)
01/01/1990 by USPSQD (GOOD)
11/02/1996 by USPSQD (GOOD)

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 June 1991.
  • 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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