From the record
“The Carbella Bridge was a historic bridge near Gardiner, Montana crossing the Yellowstone River in Park County. The bridge carried Tom Miner Creek Road.”
Wikipedia article Carbella Bridge, CC BY-SA 4.0.
One of 35 National Register listings published here for Park County · listed in 2010 · category: Structure.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service

