Nature treasures - Saturday, March 12 - Jug Bay Sanctuary will hold a "Letterboxing" program from 9 a.m. to noon at 1361 Wrighton Road, Lothian. Participants will use map-reading skills to search for hidden treasure boxes in the preserve. Meet at the Wetland's Center to carpool to the Glendening Preserve. Children should be at least 8 years old. Materials will be provided for the search. Entrance fees apply. 410-741-9330.