The "Maryland: Mountains to the Sea" exhibit (National Aquarium in Baltimore) consists of four exhibits and eight graphics panels. The exhibits are an Allegheny pond and a salt marsh which are both partially open, Assateague beach which includes birds, and the continental shelf. A variety of Maryland pond and ocean fish, crabs, and water birds are displayed in the exhibits. The graphics panels include information on the water cycle, the Chesapeake Bay, the productivity of the marsh and the bay, and information on the continental shelf. This guide is designed to be used in conjunction with a trip to this exhibit. The trip fits well with units that include topics related to the ecology of a pond, marsh, or estuary, Maryland geology and geography, the Chesapeake Bay, food webs, and the water cycle. The guide include: (1) introductory information about the exhibits; (2) pre-visit activities suggestions; (3) post-visit activities suggestions (including a water cycle crossword puzzle, information on and procedures for constructing a simple model estuary, a geography exercise on the Chesapeake Bay, procedures for making a hydrometer, and other activities); (4) a list of suggested readings; and (5) a list of suggested films (keyed by location and age/educational level). (JN)