On 2 May 2000, the United States government made a decision that, while framed in technical language about satellite accuracy, would eventually inspire millions of people to wander through forests, scale hills, and peer under park benches in search of hidden containers. The decision was the deactivation of selective availability — the deliberate degrading of GPS signal accuracy that the military had maintained since the system's civilian rollout. With selective availability switched off, the accuracy of consumer GPS devices improved dramatically, from roughly 100 meters to around 10 meters or better. The era of precise civilian GPS had arrived, and one man in Oregon had an immediate idea about what to do with it.
Dave Ulmer, a technology enthusiast, placed a black plastic bucket in the woods near Beavercreek, Oregon, on 3 May 2000 — the day after selective availability was deactivated. The bucket was partially buried and contained a variety of items: software, videos, books, money, a can of beans, and a slingshot. He posted the exact coordinates — 45°17.460' North, 122°24.800' West — to the Usenet newsgroup sci.geo.satellite-nav, inviting anyone with a GPS receiver to try to find it. Within three days, the cache had been found twice, the first finder being a man named Mike Teague. What Ulmer had conceived as a simple experiment in GPS precision quickly captured the imagination of an online community eager to explore the possibilities of the newly accurate technology.
The activity needed a name. Ulmer had originally called it the GPS stash hunt, or gpsstashing, but the word "stash" quickly became a point of concern within the online community that had gathered around the new hobby. The connotations of the word — illicit hoarding, hidden contraband — were felt to be unhelpful for an activity that organizers hoped would be embraced by families and outdoor enthusiasts. A member of the online discussion group suggested the term geocaching, combining the Greek prefix geo, meaning earth, with caching, the practice of hiding supplies for later use. The term was adopted, and the activity has been known by that name ever since.
As a hobby, geocaching drew on older traditions while creating something distinctly new. Letterboxing, a similar pursuit that involves finding hidden containers using written clues, had originated in Dartmoor, England, in 1854, and the spirit of outdoor puzzle-solving and hidden treasure that animated it was clearly ancestral to geocaching. Orienteering, treasure hunting, and trail blazing also share family resemblances with the activity. But geocaching's use of GPS coordinates gave it a precision and a scalability that none of its predecessors had possessed. A cache could be hidden anywhere on earth and its exact location encoded in a string of numbers that any GPS receiver could interpret. The activity was inherently global from its inception.
The mechanics of geocaching are deliberately simple. A typical cache is a small waterproof container holding at minimum a logbook and often a pencil or pen. Finders sign the log with their chosen username and date their entry, providing physical proof of the discovery. After signing, the cache must be returned to precisely the position in which it was found. Larger containers can hold small trinkets and toys available for trade, with the convention being that anything taken should be replaced by something of comparable or greater value — items with sentimental rather than monetary worth. The cache must never be removed from its hiding spot.
The activity grew with remarkable speed through the early years of the internet era, aided by the establishment of dedicated websites and organizations to manage listings and coordinate the community. Groundspeak, the company behind the principal geocaching platform, became the custodian of the growing worldwide database of caches. By 2023, there were over three million active caches registered worldwide, distributed across every country on earth and in environments ranging from urban parks and suburban backyards to remote wilderness and international landmarks.
The hobby developed its own subcultures and specialized variants. Trackable items — objects with unique codes that finders could log and then move to different caches — allowed participants to follow the journey of a single object across continents and years. The most famous of all trackable items is the Original Can of Beans: the only item salvaged from Ulmer's original cache after the bucket was destroyed by a lawn mower. The can was eventually turned into a trackable, giving it a second life as a physical artifact of the hobby's founding moment. A commemorative installation called the Original Stash Tribute Plaque now marks the site of the first cache.
In 2008, geocaching expanded beyond the planet itself. Richard Garriott, a game developer who traveled to the International Space Station as a spaceflight participant, placed the first extraterrestrial geocache on board the station. The cache, designated GC1BE91, used the Baikonur Cosmodrome in Kazakhstan as its listed coordinates and contained a Travel Bug — the first geocaching trackable item in space. Because of fire regulations aboard the station, it contained no paper logbook. The Travel Bug remained aboard until it was returned to Earth in 2013. By June 2024, only one confirmed finder had officially logged the cache, though others had made varying claims. In 2021, geocaching reached Mars when a trackable item was attached to the SHERLOC instrument's calibration target on NASA's Perseverance Rover, which landed on the red planet on 18 February 2021.
The activity's enduring appeal lies in its combination of simple technology with the ancient pleasure of the hunt. For participants, the world is perpetually full of hidden things, and the next discovery might be tucked under a loose stone in a city park, inside a magnetic case attached to the underside of a bridge railing, or at the end of a two-hour hike through old-growth forest. The hobby has introduced millions of people to landscapes they might never otherwise have explored, and has built a global community united by the shared enjoyment of finding what others have deliberately hidden for them.
