southpawaz

Yes I think it's safe to say that they did not take the height of the tower into account. Looking at the topo map I would put the height of the ground at the tower somewhere between 510 and 520 feet (not used to seeing 10' contour lines!).

Per the data sheet: CQ2886.The orthometric height was scaled from a topographic map.

Noticed these lichens on red rock while out for a drive yesterday and thought of kayakbird. ET0905 SPRING is up on top of the hill (more easily accessed from the other side).

Mike, it looks from your photo like the P-K and washer is on a tree, and looking at the topo map for the nearby mark you cited, I see a section line intersecting the lake nearby. My guess is that the nails mark bearing trees for a meander corner (which would be located where the section line intersects the Ordinary High Water Mark of the lake) or a witness corner for a meander corner. See 1973 BLM Manual, ss 3-115 to 3-123 Meandering.

DragonsWest, One of the differences between geodetic survey marks and cadastral marks is that geodetic marks are generally placed, and then their location (horizontal and/or vertical) is determined. With cadastral marks, the location is determined first, and the monument is set to mark that specific location. When the cadastral surveyor finds that it is not physically possible to place a monument at a surveyed location, they may set a reference monument such as the one you found to indicate that location. The exact bearing and distance to the surveyed location would be recorded in the field notes and/or on the survey plat. So, I would say that it is less likely that anything was destroyed, and more likely that there was never a monument at the indicated distance to begin with.

Mike, I consulted with Deb Brown about a similar situation (disk reset but reset not documented) with regard to DU2086 SUPERSTITION, and was advised that a found it log describing the discrepancy was appropriate. Here's the text of my NGS log: It appears that sometime after the last recovery report in 1946 the original aluminum station disk was damaged, and the disk was reset by the USGS in 1965 without being documented with the USC&GS. The three reference marks are still in place as originally described when set, and field measurements from each reference mark to the station were all accurate to within .01 meters, indicating that the reset station is very likely in the same location as the original disk. The reset station disk is a standard USGS Bench Mark disk stamped 1910 SUPERSTITION RESET 1965 U.S.C.G.S 1946.

While I agree with 2of that the North Rim has definite plusses over the South Rim, it is a long way around to it if you don't have other things you want to do on the north side. In September, with kids back in school, the South Rim won't be quite as overrun as it is during the summer, and if you plan to get there first thing in the morning you can see whatever sights interest you without feeling the crowds too much.

Nails are generally used for temporary control points (horizontal or vertical or both). They may also be used to monument property corners where a corner falls on asphalt, for example. The information on the washer or shiner is likely the registration number of the surveyor who set the nail. The fact that it has identification leads me to believe it would be boundary related rather than a control point. If you keep your eyes open for these kinds of marks, you're likely to see them everywhere you go.

While this thread was started to discuss USC&GS disks rather than USGS disks, I'll venture off topic a bit since kayakbird brought my name up. The USGS was using 4 inch disks in that time frame. AZcachemeister and I last month recovered ET0856 NEW RIVER, a USGS station monumented with a 4 inch disk circa 1900. It is a bit different than yours, however, as it is aluminum and flat rather than domed. My recollection is that the "golden" disk in the photo that kayakbird cited was 3 inches, not four. On a sad side note, the Lookout Tower that sat above ESCUDILLA was recently lost in the Wallow Fire.

Nice article, thanks for the link. Seems as good a place as any to plug a geocache AZcachmeister and I hid last month, GC2WCPX Signalman Jasper S. Bilby.

I don't know if this is actually being done or not, but one possibility could be that recoveries are being submitted via OPUS, and data then transferred to the traditional data sheet.

On the NGS site you can do a search of an area given a lat/long and radius (or alternatively a rectangular area). Without knowing where the base is, I searched on a point in the center of the island with a radius of 20 miles and came up with BF4530 and two others which have no descriptive data in the database other than their locations. They are: Happy hunting and thank you for your service!

There is a version of BMGPX that runs at the command line in OSX as discussed in this older thread, but the links to it therein appear to no longer be valid. If you send me your email address via a note through my profile on here I can forward you a copy of the executable and source code.

I have a Harbor Freight 165'/50m 1/2" fiberglass tape, SKU 35712. $10, made in China, not super durable but I don't use it too often. Metric scale as well as inches and feet so I don't need to convert from the metric on the datasheet.

Be sure and get the agency correct when you do your waymark: USGS /= USC&GS.

I was a bit pressed for time when I posted this morning. Found it by converting your coordinates to DMS and plugging in to the NGS Radial Search function.

Looks to me like it's probably reference mark 2 for KT2014, which was last reported as not found in 1980.

Here's an example of what Kurt describes. One that I've found is pictured below. It is on the east boundary line of the township so it has hashes chiseled indicating 2 miles to the north township line and 4 miles to the south township line. Interior corners would typically have the hashes indicating distance to the south and east lines.

I visited ET0934 HORSETHIEF LOOKOUT last weekend. The sequence of events regarding the marks there was as follows: 1935 - Forest Service sets disk under center of the tower. 1946 - C&GS uses the Forest Service disk, adds two reference marks and an azimuth mark. 1968 - USGS uses the Forest Service disk, adds its own reference mark.

Here's Horsethief Lookout Tower, standing guard above ET0934 HORSETHIEF LOOKOUT:

I'm pretty certain that this would not be a triangulation station, despite the triangle in the center. A triangulation station would typically not have an elevation attached to it as stamped on this one, and being so close to the building would significantly affect the sight lines needed to triangulate its horizontal location. Most likely a bench mark disk, with accurately measured elevation but not location.

Yes, I remember missing one when I misread the bearing of the call to the witness post, and the monumentation style was one I hadn't seen before. It was a brass cap on a pipe, below grade with a threaded PVC sleeve and a plug screwed into the top: CG0868.

I've used the method John describes with good success on some back-road level runs. It's especially helpful when you're hunting in the reverse direction of the described route. I was just yesterday using the method you described, Bill, to try and puzzle out the location of a couple of azimuth marks, though I was using NG Topo and drawing the segments of the route rather than checking against the elevation profile.

I was thinking NM, but you're right NV looks like it would be a good choice, not so many counties. I'll be finishing off Imperial CA when I'm down there in a couple weeks.

DV1907 HARQUAHALLA RESET is the highpoint of La Paz County AZ but it's listed in Maricopa County. The county line runs north/south through DV2275, about 3/4 mile to the east.