From the record
“The Cross Ranch Archeological District near Hensler, North Dakota is a 6,365-acre (2,576 ha) historic district that was listed on the National Register of Historic Places (NRHP) in 1985.”
Wikipedia article Cross Ranch Archeological District, CC BY-SA 4.0.
One of 1 National Register listings published here for Oliver County · listed in 1985 · category: District.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service