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The NMNH GeoTrail is open!

Discover Natural History and your National Museum of Natural History on the NMNH GeoTour!

The National Museum of Natural History GeoTour consists of 9 caches.  The caches on the tour are Puzzles or EarthCaches and thus require questions to be answered to find the coordinates to the final or satisfy the requirements of the EarthCache.  These caches are complex and may include web searches, museum visits, and field puzzles.  By completing the tour of caches you will learn about some natural history topics and about the wide scope of activities that take place behind the exhibits at the National Museum of Natural History.

The NMNH GeoTour will introduce you to some of the scientific departments (we anticipate adding more caches to the tour in the coming year).  Additionally and not an actual part of the tour; we plan on hosting a number of events in the field, which we are informally referring to as “The Doctor is Out”; during which one or more of the museum scientist will give an informal presentation about research they personally are conducting and be available for open discussion.

The nine caches will take you on an archaeological and geological trip to the area near South Mountain, PA; a visit to a wetland habitat in an area that once was part of a military base that is in the process of returning to its natural habitat; go on a dinosaur hunt just south of Laurel, MD; as well as expose you to corners of NMNH exhibits and web sites that you might have overlooked.  You will learn about active research and how that research improved the safety of the traveling public as well as how the research being done is making significant changes to our understanding of the peopling of North America, a current topic which has fostered much controversy and debate in the archaeological community.

By completing the original 9 caches you will be awarded an NMNH GeoTour emblem for your profile page.  To receive the url to the web page, from which the emblem can be down loaded, you will have to print-out the NMNH GeoTour Passport.  As you find and log the different caches the passport must be filled out, including all the required passwords, and mailed to the listed address.

As some of the Unknown (puzzle) caches involve field puzzles we have provided checksum digits which will allow you to determine relatively quickly whether you have the correct coordinates.  A checksum digit is simple addition:  N75° 57.987 has a checksum digit of 3.  To arrive at this number sum 7+5+5+7+9+8+7 = 48; sum 4+8 = 12; sum 1+2 = 3

Come and experience Natural History through geocaching!!

To get started learn more about Geocaching and then visit the NMNH GeoTour Passport page to down load the passport.

To participate in Smithsonian NMNH Geocaching / GeoTour activity, users must register at, which is a third party website owned operated by Groundspeak, Inc. which is the primary facilitator for the Geocaching community worldwide.  Please be advised that / Groundspeak Terms of Service ( and Privacy Statement ( applies to your use of these services. The links to are provided for participation and informational purposes only, and they do not indicate the Smithsonian’s endorsement, sponsorship of, or affiliation with or Groundspeak Inc. or content of those websites, including any advertisements that may be posted. The Smithsonian has no control over, makes no representation or warranty and bears no responsibility for the accuracy, legality or content of the externally linked sites. For more info on the Smithsonian Terms of Use, see: and the Smithsonian Privacy Policy at:

Geocaching is an activity in which participants use a hand-held GPS (Global Positioning System) to plot map coordinates in order to locate a hidden treasure or "cache. Searching for a cache is akin to going on a treasure hunt and can involve clues, riddles and visits to multiple locations.

A "GeoTrail" is a series of caches tied together by a common topic or theme. Learn more ...

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