2) Celebrate the first anniversary of the Appalachian Trail Museum all weekend. The museum, located near the midway point of the 2,181-mile, Maine to Georgia trail, showcases and honors the legendary hikers who made the idea for a footpath a reality. Hikes, music, speakers and children’s programs will fill both days. The museum is in Pine Grove Furnace State Park in Gardners, Pa., not far from Gettysburg. A list of programs is at the museum website.

3) Learn about native butterflies Saturday during a 2.5-mile guided walk at the Patuxent Research Refuge North Tract in Laurel. The program, suitable for those over 10, begins at 8:30 a.m. A field guide recommended. Bring water and dress for the outdoors. Save a spot by calling 301-497-5887.

4) Go fishing with dad on Sunday at Patapsco Valley State Park or take a hike at Soldiers Delight Natural Environment Area. Fishing will take place from noon to 1:30 at Lost Lake in the Avalon area. Bring drinking water and your favorite bait. Bring a fishing pole if you have one, but there will be extra poles if you need them. This activity is for dads, and children under 16. The cost is $2 per father and child. The 90-minute Soldiers Delight hike begins 4 and will be led by a naturalist. The walk through the sprawling Serpentine Barrens will touch on history, geology and ecology. Afterward, participants will get the chance to meet native wildlife that lives in the aviary. The cost is $5 per person. Reserve a spot for either activity by calling 410-461-5005.

5) End the weekend with a good deed. REI Timonium will be collecting used two-wheelers for Bikes for the World from noon to 4 p.m. Sunday. Bikes for the World works with partner charities in developing countries that train and hire local people to recondition bikes and distribute them to individuals in need of affordable transportation. A $10 donation with your donated bike covers shipping and handling. Details: 410-252-5920.