The Sinnott Memorial Observation Station was built into the caldera cliff overlooking the lake. The structure was designed by landscape architect Merel S. Sager, a pioneer of the rustic style of park architecture. The building includes a small natural history museum with exhibits that highlight the geologic history of Mount Mazama and the formation of Crater Lake. The building was officially dedicated on 16 July 1931 as the Nicholas J. Sinnott Memorial Observation Station and Museum. The Sinnott Memorial was listed on the National Register of Historic Places in 1988 (NRHP #88002623).