While on a recent caching adventure in VT, I ran into a fellow cacher and avid Benchmark Hunter. He had many stories about BW miles into the woods with his metal detector and finding remote benchmarks that hadn't been found in 100 years. I noticed when I got back that many cachers seem to ignore benchmarks. Looking at some local power cachers with finds in the 5000 range, I was shocked to see that many had fewer than 5 benchmarks...and most of those were landmarks. That along with finding some really neat benchmarks recently myself, I figured a benchmarks challenge was called for!
What are these Mysterious Benchmarks you ask? A benchmark is a point whose position is known to a high degree of accuracy and is normally marked in some way. The marker is often a metal disk made for this purpose, but it can also be a church spire, a radio tower, a mark chiseled into stone, or a metal rod driven into the ground. Over two centuries or so, many other objects of greater or lesser permanence have been used. Benchmarks can be found at various locations all over the United States. They are used by land surveyors, builders and engineers, map makers, and other professionals who need an accurate answer to the question, "Where?" Many of these markers are part of the geodetic control network (technically known as the National Spatial Reference System, or NSRS) created and maintained by NOAA's National Geodetic Survey (NGS). For more detailed information check out the related webpage link. For this challenge we are dealing with the metal disc markers exclusively.
Now to the details of the Challenge:
TO COMPLETE THE CHALLENGE YOU MUST have logged at least 25 GEODETIC SURVEY Discs.
Here is the list of ALL THE DISC types that will Qualify:
Other types of Benchmarks do not count towards this total, just discs. I'd say the majority of discs you will find are TRIANGULATION STATION discs. Make sure you check the PID to see how many discs are in each. Usually you will find the PID listing includes both the TRIANGULATION STATION and two REFERENCE MARK discs, and maybe an AZIMUTH Disc all under one PID. Sometimes you will find each has its own PID. The Main TRIANGULATION Station will have it's own PID, and RM#1 will have its own PID, and RM#2 will have its own PID. In this case you can count each the TRIANGULATION STATION and each REFERENCE MARK as a separate find, because there are 3 PID's.
- Astro pier disk
- Bench mark disk
- Traverse station disk Gravity station disk
- Horizontal control disk
- Tidal station disk
- Gravity reference mark disk
- Magnetic station disk
- Base line pier disk
- Calibration base line disk
- Reference mark disk
- Triangulation station disk
- Topographic station disk
- Vertical control disk
- NOS hydrographic survey disk
- Azimuth mark disk
To Verify your completion of the requirements I will check your public profile & make sure you have the 25 required.
Although I won't require the following, I HIGHLY ENCOURAGE IT !!!!!! It would be awesome if each find was documented with a photo of each disc and your GPSr to verify coords...extremely helpful as you'll notice a lot of benchmark discs are not even close to the given coords & it would help fellow BM hunters following in your tracks.