Butch Femme Planet - Letterboxing

"Do you enjoy getting out into the great outdoors? Are you looking for an activity the whole family can enjoy? Letterboxing combines elements of a scavenger hunt, hiking, orienteering, map reading, puzzle solving and creative expression in a unique activity that's growing in popularity. There are more than 22,000 letterboxes hidden in the U.S. today, but you'll only find them if you can correctly follow the clues. Once you've found a letterbox, record your discovery in its log using your personal rubber stamp, and stamp the letterbox's stamp in your personal journal."

http://letterboxing.net/

"LETTERBOXING is an intriguing pastime combining navigational skills and rubber stamp artistry in a charming "treasure hunt" style outdoor quest. A wide variety of adventures can be found to suit all ages and experience levels."

http://letterboxing.org/GettingStarted.php