| About.com: Letterboxing and Geocaching Attract Walkers: Article describing the basics and the factors that motivate people to start letterboxing. | |
| Aisling Dart: Artist from Salem, Massachusetts describes her boxes. | |
| All Info About Raising Boys: Letterboxing Family Fun: Brief article includes details on supplies and features instructions for participation with children. | |
| Atlas Quest Letterboxing: Trip planning portal offers clue search by country as well as tutorials and premium members services. | |
| Brett and Penny's Letterboxing Page: List of their boxes planted, found, and exchanged, primarily in Oregon and the Pacific Northwest. | |
| British Columbia Letterboxes: Introduction, photographs of personal stamps, and clues for boxes planted in southwest British Columbia. | |
| Buckaroo's Letterboxing: Clues for boxes she planted in Washington and Massachusetts. | |
| Catbead Mischief: Offering clues for letterboxes in the Syracuse, New York area. | |
| Chowder's Southern California Letterboxes: Search for boxes in Long Beach, San Bernardino and Lake Arrowhead, California. | |
| Chuck's Letterboxing: Chuck and Molly's letterboxes in Connecticut. | |
| Connecticut Department of Environmental Protection: Letterboxing: Official site supports letterboxing in publicly owned state forests. | |
| Dartmoor Letterboxes: Introduction, tips and things to avoid, news, survey, and letterbox clues for the Dartmoor area. | |
| DartmoorLetterboxing.org: History of the activity, similar to orienteering, begun in 1854 at Cranmere Pool on the moor, and now popular in many countries. Offers a forum and contact information. | |
| Der Mad Stamper: Rubber stamp carver Mitch offers instructions on how to carve a stamp, and some examples. | |
| Dutch Letterbox Site: Clues for boxes in Dartmoor and in the Netherlands. [English and Dutch] | |
| First Finds: Posts first finds submitted by new US letterboxers, organized by state. | |
| Fish and Chips' Letterboxing Paradise: Virtual letterbox clues lead visitors on an online hunt. | |
| Fleur de Lis' Letterboxing Journal: Weblog about his letterboxing hobby. | |
| Fox News: Letterboxing Makes Hiking an Adventure: Feature story datelined Oakland, New Jersey. | |
| Fudrick's Letterboxing Travails: Clues to letterboxes he has placed, mostly in the Northwest US. | |
| Have Feet Will Travel: Introduction, contact details, and guidelines for letterboxing in the Dartmoor area. | |
| History of Dartmoor Letterboxing: Account first published as "More Dartmoor Letterboxes" by Anne Swinscow in 1986. | |
| Hitchhiker List: Hitchhikers are a form of traveling letterbox. Site includes lists of hitchhikers and last reported letterbox location. | |
| Holcomb Farm: Clues to boxes hidden in Granby, Connecticut. | |
| I-95 Letterboxes: Clues to quick and easy letterboxes to find while traveling on Route I-95, from Maine to Florida. | |
| Kansas Letterboxes: Clues for letterboxes located in Kansas. | |
| Letterboxers Anonymous: Forum with clues and discussion topics. Includes helpful hints on methods and supplies. | |
| Letterboxing Germany: Clues for Germany and other European countries. Includes photos and tips. [English, German] | |
| Letterboxing North America: US-based portal offering FAQ, links, forums, and a members-only section where clues can be submitted. | |
| Letterboxing Northeast: The Drew family of East Lyme, Connecticut, offer clues in New England states as well as Washington, DC, South Carolina, and Colorado. | |
| Letterboxing Questionnaire: British university student studying letterboxing for her dissertation asks visitors to answer a few questions on the activity. | |
| Mark and Sue Pepe: Couple from Kensington, Connecticut describe activities in eleven states and the island of Aruba. | |
| Massachusetts Letterboxes: Bonnie and Betsey Sennott offer clues to their boxes in Massachusetts. | |
| Mirkwood's Letterboxing: Clues to boxes placed by Ruthann Zaroff and her family throughout Michigan, plus images of the stamps she created for them. | |
| MommaFox and Bald Eagle: Anna and Paul offer clues to boxes in Connecticut, Massachusetts and Vermont. | |
| Nebraska Letterboxing: Information about letterboxing in and around Nebraska. Includes clues and logs for local letterboxes, as well as some resources for letterboxing in general. | |
| NeeDeep's State Stamp Letterboxes: Ambitious family project placing letterboxes in each state, patterned after the US quarters series. | |
| New England Area Letterboxing Gatherings: Mark & Sue's blog of letterboxing events in New England. | |
| New Zealand Letterboxing: Clues, views, and news including boxes from Team Psychokiwi, Judi, Linton, and the Bunny. | |
| North America Webring: Links to dozens of forums and clue sites. | |
| NPR : Letterboxing: Radio host Linda Wertheimer and Thomas Johnston, an enthusiast in Washington, D.C., find a letterbox near the White House. [audio] | |
| Oklahoma City Letterboxes by Dennis Williams: Clues to boxes in Oklahoma City as well as New Mexico, Alabama, and Costa Rica. | |
| Perfect Circle Letterboxing Guild: Family and friends offer clues to letterboxes in New Jersey and Pennsylvania. | |
| Ryan's Letterboxes: Personal page with clues for boxes placed throughout the western United States, as well as a few in Canada, Africa, and Central America. Also includes tips for improving the stamp quality. | |
| Silent Doug's Letterboxing Site: Articles including getting started, outdoor ethics, and explanation of cryptic letterboxer codes. Also includes list of boxes found and clues for boxes placed in New York and Pennsylvania. | |
| Silver Eagle's Letterbox Aerie: Clues to nearly 100 letterboxes that Silver Eagle has placed in North America, primarily in Texas. | |
| Smithsonian Magazine: They Live and Breathe Letterboxing: Abstract of an article by Chris Granstrom, with link to a few references. | |
| Stamp-in-the-Box: A collection of information and clues relating to letterboxing, a hobby that combines hiking, art, orienteering and mystery in a treasure-hunt style activity. | |
| Steve's History of Dartmoor Letterboxing: This Englishman from Torquay has written a brief history with a guide to the Tors and some examples of stamps. | |
| The Gazette: Letterboxing a Hobby of Inky Fingers and Hidden Treasures: Article on local letterboxing from chain of community newspapers near Washington, DC. | |
| The Space Traveler: Family offers clues for Pennsylvania, New York and other states. | |
| The World of Letterboxing Community: Forums and worldwide clues database. | |
| Twograysquirrels Letterboxes: Clues to letterboxes placed by twograysquirrels, mostly in Maryland and Virginia. | |
| Urban Letterboxing: Database of clues to letterboxes in urban locations, primarily in Europe. | |
| Wanda and Pete's Letterboxes: Clues for boxes placed primarily in Rhode Island, but a few in other states as well. Also includes logs of the movement of hitchhiker boxes, primarily in New England. | |
| Washington Post: Thinking Inside the Box: Article by Caroline Kettlewell describes her discovery of the activity. | |
| What is Letterboxing?: Michelle Spalding offers a history of letterboxing in England and the United States with bibliography. | |
| Yahoo! Groups: Letterboxing Northeast: Discussion group for the northeastern US. | |
| Yahoo! Groups: Letterboxing USA: Discussion group for US letterboxers. |
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