From the record
“The Otter Spring House is a historic spring house in the Town of Lincoln in Forest County, Wisconsin. The spring house was built on Otter Spring in 1933 as a Civilian Conservation Corps project.”
Wikipedia article Otter Spring House, CC BY-SA 4.0.
One of 9 National Register listings published here for Forest County · listed in 1999 · category: Building · built in 1933.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service
