From the record
“Woodruff Cabin Site is the location of the first European-American settlement in the Big Horn Basin of Wyoming. John Dwight Woodruff built a cabin on Owl Creek in Hot Springs County in 1871.”
Wikipedia article Woodruff Cabin Site, CC BY-SA 4.0.
One of 12 National Register listings published here for Hot Springs County · listed in 1970 · category: Site.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service