From the record
“The Oliver and Lucy Bonnell Gothic Arch Roofed Barn in Park County, Montana, or simply the Bonnell Barn, is a Gothic-arch barn which was built in 1922. It was listed on the National Register of Historic Places in 2004.”
Wikipedia article Oliver and Lucy Bonnell Gothic Arch Roofed Barn, CC BY-SA 4.0.
One of 35 National Register listings published here for Park County · listed in 2004 · category: Building.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service