The Carson Trail was built by volunteers, Maine Conservation Corps, Youth Conservation Corps, and staff in 1988 after 3 years of hard work. Trail design takes advantage of a natural isthmus and the confluence of Branch Brook and the Merriland River to form the Little River. The compacted crushed-stone tread is outlined with 1x6 planks, bent to the undulations of the trail. Hand rails, where present, are mounted on taper-cut 4x4 timbers and interior-fastened, overlapping 1x2 stock. Framing and handrails on the older sections of the trail are pressure treated yellow pine. Sections rebuilt after a dramatic landslide use plastic lumber.
The trail is set back from the river banks by the width of three to six trees. The red maples, birches, alders, oaks and black cherry are mature allowing excellent views without direct disturbance. Eleven interpreted stops provide overlooks, benches and information on area wildlife. Most of the stops offer views of salt marsh pools and pannes with the Gulf of Maine in the distance. Newer uplands are dominated by eastern white pine, balsam fir and red spruce.
An interpretative brochure covers the coastal wetlands and wildlife habitat, as well as the author, Rachel Carson. The trail transverses three habitats, upland hardwoods, shrub-scrub and salt marsh. The varied structures and edges provide excellent wildlife habitat. Migratory birds are the most prevalent species present, but otter, deer, moose, coyote, bear, and turkey have all been seen from the trail.
