Naples, Idaho is on which 2571 mile-long highway that runs across the northern US?
Naples, Idaho:  It lies 11 miles (18 km) south of the city of Bonners Ferry and 23 miles north of Sandpoint, on U.S. Routes 2/95 in the Rocky Mountains. U.S. Route 2: U.S. Route 2 or U.S. Highway 2 (US 2) is an east–west U.S. Highway spanning 2571 mi across the northern continental United States.
U.S. Route 2