Sledders cross the Philpott Bridge as they enter a section of the Katahdin Woods and Waters National Monument in North Penobscot. Kevin Bennett Photo

Norman Ricci of Providence, R.I., voices his opinion about Roxanne Quimby and the national monument that she helped to create as he and snowmobiler Bob Santoro of Hopkinton, R.I., take a break at the intersection of ITS 85 and 114.

Blaine King grooms the Katahdin View Loop snowmobile trail inside the Katahdin Woods and Waters National Monument.

A group of snowmobilers stops to take in the view on the Katahdin View Loop trail.

Small boundry signs, accompanied by blue paint on trees, are the only indication that a border is being crossed at the Katahdin Woods and Waters National Monument.

Riders race their snowmobiles south on ITS 85, which winds through four different sections of the Katahdin Woods and Waters National Monument.

A group of snowmobilers stops to inspect a sled at the intersection of ITS 85 and ITS 114 in North Penobscot.