[2] In much of Cameron and Clinton counties, PA 120 is a Pennsylvania Scenic Byway designated the Bucktail State Park Natural Area.

[3] Bucktail State Park Natural Area runs 75 miles (121 km) from Emporium to Lock Haven, and is named for the Pennsylvania Bucktails Regiment, who came from the area during the American Civil War.

PA 120 and the park run along Sinnemahoning Creek and the West Branch Susquehanna River and also pass through Renovo (in Clinton County).

The law establishing the park defined its boundaries as "all that area of land extending in length from the western city line of Lock Haven, in Clinton County, to the eastern borough line of Emporium, in the Cameron County, and along the course of the western branch of the Susquehanna River, and its tributary, Sinnemahoning Creek, in Clinton and Cameron counties, an estimated distance of 75 miles, and in width from mountain rim to mountain rim across the valley.

[6] The portion east of Lock Haven of the remainder of the route became US 220, US 15, and US 122 ca.