A celebration of National Trails Day in Pioneer Park on Saturday, June 4, will include letterboxing, known as the “outdoor treasure hunting pastime.” During the event, the Mercer Island Parks and Recreation Department will have a booth located off S.E. 68 Street in Pioneer Park, across from the South end Starbucks, offering nature-based arts and crafts, hiking activities and letterboxing.

Letterboxing is a mix of treasure hunting, rubber stamp artistry and puzzle solving. Letterboxers hide small, weatherproof boxes in public areas such as parks and distribute clever clues for finding the boxes. Hunters decipher clues, search for boxes, and use personalized rubber stamps to track their discoveries in logbooks.

This year’s event is supported by donations from Holland America Line and the Mercer Island Lion’s Club. Event partners include Starbuck’s Coffee, the Mercer Island Open Space Conservancy Trust, Mercer Island Parks and Recreation, the Mercer Island Boys and Girls Club, and the Boy and Girl Scouts. National Trails Day is sponsored by the American Hiking Society as part of their mission to promote and protect foot trails and the hiking experience.

For more information on National Trails Day and letterboxing, contact the Mercer Island Parks and Recreation Department at www.miparks.net or (206) 275-7609.