For more information about Preservation Parks of Delaware County or to register for a program, call 740-524-8600, extension 3 or email register@preservationparks.com. The parks are open every day from 8 a.m. to 9 p.m. Facility hours will not change. Visit preservationparks. com for additional information.

For more information about Preservation Parks of Delaware County or to register for a program, call 740-524-8600, extension 3 or email register@preservationparks.com. The parks are open every day from 8 a.m. to 9 p.m. Facility hours will not change. Visit preservationparks. com for additional information.

Summer Letterbox Adventure returns May 23. Children register for the program, then take booklets into the parks to follow nature clues and find camouflaged boxes hidden in eight of the Preservation Parks preserves.

Participants have until Aug. 2 to conduct searches on their own time.This year's theme is "Conservation Superheroes." In addition to reading fun nature facts, children will be introduced to people who have made a difference to the environment in America, such as environmentalist John Muir and John James Audubon, naturalist and painter.

Children who find at least six boxes will be entered in a drawing for prizes donated by area businesses. Those who find all eight will receive a pair of mini binoculars, compliments of Preferred Wireless. They also could win a personal nature program with a naturalist through a new Facebook contest: "Picture Yourself! Summer Letterbox Adventure." Sign-up starts May 23 and continues throughout the project at any Delaware County library.

Sponsors of this year's Summer Letterbox Adventure are Preferred Wireless, the Columbus Zoo & Aquarium, Taranto's Pizzeria, REI, and Fundamentals Parent Teacher Bookstore, along with the Delaware County District Library, Community Library in Sunbury, and Wornstaff Memorial Library in Ashley.

Registration is not required for the following free programs:

* Railroad Fun, noon to 4 p.m., Sunday, May 17. Watch model trains while learning about the history of railroading in America. Free; all ages. Big Walnut Community Trail house, 168 S. Vernon St.

* Continental Connection, 8 a.m. to 4 p.m., Sunday, May 17. May is Rainforest Awareness Month. See how what we do here in Ohio affects this tropical habitat. Start at the Lodge at 8 a.m. for a warbler walk and coffee. At 10 a.m. participate in a "follow-the-frog" demonstration and meet an exotic animal. Activities and games will be available from 11 a.m. to 4 p.m. Free; for all ages. Deer Haven Preserve, 4183 Liberty Road, Delaware.

* Sounds of the Night Hike, 9 p.m., Friday, May 22. Listen to the sounds of the night and learn what is making them during this hike in the woods and fields. Call for owls, listen for late spring frogs and enjoy nature at night without the aid of light. Free; ages 6 and older. Emily Traphagen Preserve, 5094 Seldom Seen Road, Powell.

* Hike for Health, 1 p.m., Saturday, May 23. Get healthy this summer! This hike begins the summer FLEX (Free Local EXercise) program, which includes exercise stations along the nature trails. The hikes are free, but a $5 fee is charged for the program t-shirt. Join us for all the hikes and receive an iron-on patch to add to your shirt. All ages. Gallant Woods Preserve, 2151 Buttermilk Hill Road.