Waterfowl, especially Hooded Mergansers and Ring-necked Ducks, in early spring migration; Wood Ducks in summer. Migrants and woodland breeding birds in spring and summer. Brown Creeper, Red-breasted Nuthatch, and Golden-crowned Kinglet along the road beyond the gate. Rails in the marsh. Red-bellied woodpeckers also nest near the marsh at the end of the paved portion of the road. Great Horned Owl, Osprey, and Great Blue Heron nest in the rookery in the large pond (Colby Marsh) on the right beyond the gate. Killdeer, Green Heron, Belted Kingfisher on the ponds. Winter Wren, Red-eyed Vireo, Eastern Kingbird around ponds.

The 73-acre Longmarsh Preserve is located in Durham about 1.5 miles south on NH-108 from the center of town, then about 1.3 miles east on Longmarsh Road. The Preserve consists of three contiguous parcels: the Langmaid Farm (45 acres), Colby Marsh (13 acres), and Horsehide Creek (15 acres). The Preserve is bisected by Longmarsh Road. Parking for a few cars is available at the end of the road; beyond an iron gate, the road continues as a woods road and pedestrian trail. This central trail is accessible to mountain bikes, horses, as well as people on foot. Several narrow pedestrian trails branch off from Longmarsh Road, snaking through woodlands of mature oak and pine.

To reach Longmarsh Preserve from NH-101 exit 11 in Exeter, go north on NH-108 past Stratham Circle and through Newmarket for 9.0 miles to Longmarsh Road, and turn right. From US-4 and NH-108 on the north side of Durham, take NH-108 south for 2.1 miles to Longmarsh Road, and turn left. On Longmarsh Road, go 1.1 miles to the first marshes, then another 0.2 miles to a small parking area just past the last house and before the gate, which is where vehicle travel ends.

This whole area is also called Colby Marsh. An open marsh is past the end of the paved portion of the road, on both sides. At the gate, the road becomes a class 6 (unmaintained) road and serves as a broad trail through woodlands and along beaver ponds. About 0.25 miles beyond the gate, a trail begins at a break in the old stone wall that follows the large pond on the right out to a cliff and very large rock overlook. Following the trail further will lead to where the road ends at another large pond. Follow the road back past yet another large pond and through the woods to the parking area.

On Longmarsh Road about 0.4 miles from NH-108, there is an American Bison farm, where the animals are often right next to the road.

The AllTrails website has a description and map of a hike at Longmarsh Preserve.