National letterboxing convention. List of events, tickets and merchandise, accommodations, and visitors guide.

Incentive program for letterboxers based on miles hiked.

Introductory article by Ashley Schwellenbach featuring a letterboxer and the founder of Atlas Quest.

Clues, views, and news including boxes from Team Psychokiwi, Judi, Linton, and the Bunny.

Social group that has mini-meets and gatherings. Includes event schedules and photo galleries.

Official site supports letterboxing in publicly owned state forests. Includes clues and a map of letterbox sites in state forests.

Blog and Michigan clues and events.

Article by Caroline Kettlewell describes her discovery of the activity.

Ambitious family project placing letterboxes in each state, patterned after the US quarters series.