The Swift River is a premier 23-mile freestone stream that originates on Mount Kancamagus in the White Mountains National Forest near Livermore and flows through both Carroll and Grafton Counties before joining the Saco River. This clear, cold mountain stream offers exceptional brook trout fishing in a stunning wilderness setting. The river is characterized by its rushing waters, varied structure including pocket water and riffles, and gravel and cobble substrate typical of freestone streams. The Kancamagus Highway (Route 112) provides excellent access along much of its length, making it one of New Hampshire's most accessible wild trout fisheries while still offering opportunities to reach more remote stretches for anglers willing to hike.