The Brunswick Topsham Land Trust has been marking its first 25 years by running a series of celebrations and explorations. On Saturday, Aug. 14, a group of kayakers launched off Water Street to visit Cow Island in the middle of the Androscoggin River, now managed by the land trust. Michelle Moody of the Appalachian Mountain Club guided Libby Hyatt, Josephine and Jim Baker and Susan and Hannah Weedle on a three-hour tour.