the sinnott memorial observation station is a sheltered viewpoint built into the caldera cliff 900 feet above crater lake in southern oregon, united states. it is located near the rim village visitor center in crater lake national park. the structure 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 as the nicholas j. sinnott memorial observation station and museum; however, it is commonly known as the sinnott memorial overlook or sinnott viewing area. it is architecturally significant because it was the first national park service building constructed specifically as a museum and the first structure built in crater lake national park using rustic stone masonry construction. it is listed on the national register of historic places as sinnott memorial building no. 67.