From the record
“The Grand Loop Road is a historic district which encompasses the primary road system in Yellowstone National Park. Much of the 140-mile (230 km) system was originally planned by Captain Hiram M.”
Wikipedia article Grand Loop Road, CC BY-SA 4.0.
One of 38 National Register listings published here for Park County · listed in 2003 · category: District.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service
