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Lost and Found

By 2oldfarts (the rockhounders)   Fri, Jul 10, 2009

A hat trick... from '66!!

Lost and Found
Lost and Found
 
 
We had looked for these benchmarks on previous occasions, but the datasheets only gave scaled coordinates and not adjusted coordinates. We followed the coordinates to the location and then tried to follow the description on the datasheet. It's truly amazing how many rock outcrops there are on the Kaibab Plateau along side of Highway 89A. After having tried before, we decided that we needed to take a different approach for these.
 benchmark located benchmark and trees
benchmark along highway
We got the USGS Topo quads out and started looking to see if the benchmarks were shown on them. Z 51 and 6028.93 were shown on the quad maps, but not A 52. We started with Z 51 and compared the scaled coordinates with the map position of the benchmark. The map indicated that the benchmark was further north than scaled coordinates showed. We decided to go to the position shown on the map and see what was actually there and to see if it would match the description on the datasheet. When we got to the position shown on the map we were about 200 feet north of a limestone ledge that matched the description. I climbed onto the ledge and looked around for any sign of the disk. Nothing was in sight, so the next option was to get the metal detector from the truck. I went back to the ledge and started sweeping the ledge where it had been covered over with dirt and debris. In less than 5 minutes I was getting a strong signal. It turned out to be a piece of rebar driven into the limestone. Perhaps this was where they had planned on putting the witness post. I continued to sweep the area, but that was the only signal I got at that area. I moved around the ledge and found a few aluminum cans but no disk. I went back to where I had gotten the first signal and tried again. I then noticed that the signal was to strong for just the rebar, so I moved around and tried detecting from a different angle and noticed the signal was stronger to one side of the rebar. I cleaned away the dirt and debris and there was the disk. The disk was only about 6 inches from the rebar! We found what the USGS (United States Geological Survey) couldn't find in 1966!
 benchmark along highway
We headed off for A 52 after resetting the trip odometer to 0.0 since it is exactly 2 miles from Z 51. After driving exactly 2 mile we found a nice area to safely pull over and park the truck.
 
A quick look at the datasheet and I knew how far from the highway the mark was going to be. I paced off 70 feet and started walking parallel to the highway and quickly determined that going south wasn't the best choice due to the lack of outcrops. I headed north and started seeing some outcrops scattered about. I spotted a lone rock next to one outcrop so I paced SE back to the highway and the distance fit very well with the datasheet. I again retrieved the metal detector and made about 3 swings near the big rock and the detector sounded off.
 
Scraping my feet in the dirt revealed a small portion of the disk. Further cleaning revealed the disk we were searching for. We found what the NGS (National Geodetic Survey) had not found in 1966!
 pipe near highway
The last benchmark we found on this outing was 6028.93. It was placed by the Bureau of Public Roads ( US Dept of Agriculture) and last recovered in 1934. It too has scaled coordinates on the datasheet, but it has an icon on the USGS topo quads, so that is what we decided to use as a starting point. Turns out to be the best choice for this benchmark. We got to where the topo map showed the benchmark to be and safely pulled off the highway. Got out of the truck and paced off the required distance and started walking south. I only got about 20 feet when Shirley hollered to look behind me. I turned to see what she was getting excited about and there she was pointing right at the benchmark. There was no concrete showing, just the pipe with the benchmark on top.
   A52 benchmark disk 602893 benchmark disk on pipe Z51 benchmark disk
3 benchmarks not reported found in 75 years! The scenery just adds the final extra touch that makes for a good day of benchmarking!
Curving highway

By 2oldfarts (the rockhounders)

2oldfarts (the rockhounders)

We're from Northern AZ and have over 1000 benchmark recoveries. We have been GC members since 2003. We enjoy rockhounding and just being outdoors. We have a web site showing some of the great places we know about and have visited (coordinates included). http://myweb.cableone.net/rockhounders1/

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