Walk on easy trails near the Concord River and beside a wonderful freshwater marsh.

Take Rte 62 north towards Bedford from Concord Center. Turn left on Monsen Road to refuge parking lot.

Peter Alden is a Concord author and naturalist. For 55 years, he has led birders and travelers to over 100 countries on the seven continents and the seven seas. He is the author of more than 15 books on North American and African wildlife, including the National Audubon Society’s Regional Field Guide Series. On July 4, 1998 — commemorating the 153rd anniversary of Thoreau moving to the cabin he built at Walden Pond — Peter and the late Dr. E.O. Wilson organized the world’s first bioblitzes at Walden. Hundreds of specialist field biologists verified 3,600 species of vertebrates, invertebrates, plants, mosses, lichen and fungi in 3 days! Peter serves on the Thoreau Farm Trust board of directors and is part-time at the Thoreau Society Shop at Walden Pond.