Geocachers aren't the only ones combing the landscape for weather-proof containers and places to stash them.
Letterboxing has traveled across the pond to enthusiasts who enjoy treasure hunts and creating unique calling cards. Unlike geocachers, letterboxers rarely gather in social settings, which makes it harder to determine the pastime's popularity. There likely are far fewer letterboxers locally than geocachers.
"It's a very secretive society," says Connie Hart, a 55-year-old Wimer letterboxer. "Not very many people even know about letterboxing around here."
Born in England more than 100 years ago, letterboxing is a low-tech ancestor of geocaching. Written instructions and perhaps compass points or map coordinates lead the way to letterboxes, which contain logbooks and hand-carved stamps. The Internet sites, www.atlasquest.com and www.letterboxing.org, are the major repositories of letterbox clues for the United States and Canada.
When letterboxers find a box, they place their stamps in its logbook and mark their own books with the box owner's stamp. About 50 letterboxes are scattered within 50 miles of Medford, according to atlasquest.com. Many are within close proximity to geocaches, given that good locations for letterboxes appeal to geocachers and vice-versa.
Mutual respect is encouraged. Just as geocachers decry moving or destroying a cache, letterboxers do, too.
"I've had some go missing," Hart says. "And that just breaks my heart."