River Road Boat Ramp is a public access point to the Merrimack River located at the end of River Road, off N-3A. The boat ramp is open year-round and has parking spaces for vehicles with trailers. The ramp is maintained by the New Hampshire Fish and Game Department and is free to use.

The Merrimack River is a 117-mile-long river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Massachusetts, and then flows northeast until it empties into the Atlantic Ocean at Newburyport. From the point where the Merrimack turns northeast in Lowell, Massachusetts onward, the Massachusetts–New Hampshire border is roughly calculated as the line three miles north of the river.