From the record
“The Canyon Creek Shelter, also known as the Sol Duc Falls Shelter, is a rustic trail shelter in Olympic National Park. It is the last remaining trail shelter built in the park by the Civilian Conservation Corps (CCC) from Camp Elwha.”
Wikipedia article Canyon Creek Shelter, CC BY-SA 4.0.
One of 43 National Register listings published here for Clallam County · listed in 2007 · category: Building · built in 1939, National Park Service rustic, by National Park Service.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service