Benchmark hunting

Spring is around the corner and soon the geo-hunts will be in full swing. Here is an alternative to geocaching that offers some variety and fun to your quests.

Benchmark disk

A metal benchmark disk. This one is at Battery Cooper near Fort Pickens at the entrance to the harbor of Pensacola, FL.

Geocaching gets all the press these days but there are other stashing games and some of them have been around longer than geocaches.  This little disk is a benchmark.  Basically it is a survey point that was used in the days before GPS.  Surveyors and map makers established these as verified accurate positions using both a physical description and latitude/longitude. Benchmarks come in various forms and have been around for over 200 years.  Church steeples and water tanks are often used as benchmarks. Every benchmark has a detailed written description somewhere in the halls of government. These descriptions tell exactly where to find the benchmark, how to get there, what it looks like and what’s nearby. Then along came GPS, which altered the whole structure of benchmarks and gave us something else to hunt.

Geocaching dot com has compiled thousands of benchmarks along with their descriptions and GPS coordinates.  You can hunt for them just like a geocache. Keep these things in mind.  1) You may find yourself looking for a BM that’s no longer there 2) It may be on private property,  in the middle of terrible terrain or otherwise inaccessible. 3) If you are running up the numbers for your geocache count, benchmarks don’t count towards the total. 4) GPS positions can be off, so you have to also rely on the detailed physical description. Nevertheless, benchmark hunting is challenging and fun.  We do it as a diversion and an add on. It also has the advantage of giving you things to hunt where geocaches are not allowed, such as the national parks.  Most bridges have benchmarks.  So do lookouts, tunnels, peaks, monuments and other assorted structures and features. To log a benchmark, take a picture of it and log it in your geocaching dot com account.

Good hunting… Boris and Natasha

4 thoughts on “Benchmark hunting

  1. Good job on the post. Benchmark hunting and benchmarks in general can always use additional “press” as you say.

    If I can ad a few points of clarification. The term “benchmark” is used on to identify any survey mark listed by the NGS, however many of the marks listed are not true benchmarks. A true benchmark, as used by surveyors, is a mark that is used to identify elevation; a vertical elevation or height based on sea-level or another vertical reference position. The vertical component of their location is the primary purpose of the station. Triangulation stations often look like benchmarks (and are called benchmarks on, however the horizontal position of the station is its primary purpose. There may be a vertical component attached to a triangulation station, however, many times there isn’t. Church steeples and water tanks are true triangulation stations with no vertical component.

    Every benchmark (or survey mark for that matter) does have a written description somewhere. That description may, or may not be held, recorded, mapped, or otherwise catalogued by a government agency, though. Many benchmarks are set by private surveyors, engineers, or scientists for private purposes. The written description and purpose of these marks may be held by the person that set the mark, the persons or group that paid for the mark to be set, or the land owner. got their benchmark list from only one government agency, the National Geodetic Survey (NGS), but there are many other Federal, State, and local agencies that have benchmark networks.

    If you’re interested, some of my benchmark finds can be seen on my blog, the Calfornia Benchmark Hunter at


    1. Hi Kevin,

      Thanks for the post and the information. I learned a few things and hope future readers will too.

      We did a geotrip through the Paw Paw Tunnel in West Virginia last summer. It was a tunnel on the old C&O Canal, which is now a bike trail. Inside were 28 metal benchmark disks from the National Park Service. They were imbedded in the brickwork next to the towpath. We took a picture of every one. We thought we’d hit the jackpot for logging them on geocaching, but they weren’t listed. Now I know why.

      Thanks for your interest in the article. I’m going to link to your blog.

      Good hunting …. Dan Lawson


    1. Hi,

      Thanks for the post. Yes, the image is a benchmark disk. A little worse for wear but the Army Corps of Engineers is the real deal. That’s one of the challenges of benchmark hunting. It might not be there and nobody knows it. In general though we’ve found that if you hunt them on natural or man made features that are in use, they’ll be there.

      There’s another comment on the post that has some useful information in it. You might want to check it out.

      Good hunting …… Dan Lawson


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