From the record
“The Lohman Block is a site on the National Register of Historic Places located in Chinook, Montana. It was added to the register on March 19, 1980.”
Wikipedia article Lohman Block, CC BY-SA 4.0.
One of 8 National Register listings published here for Blaine County · listed in 1980 · category: Building.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service

