The Marmes Rockshelter (also known as (45-FR-50)) is an archaeological site first excavated in 1962, near the confluence of the Snake and Palouse Rivers, in Franklin County, southeastern Washington. This rockshelter is remarkable in the level of preservation of organic materials, the depth of stratified deposits, and the apparent age of the associated Native American human remains. The site was discovered on the property of Roland Marmes, and was the site of the oldest human remains in North America at that time. In 1966, the site became, along with Chinook Point and the American and English Camps on San Juan Island, the first National Historic Landmarks listed in Washington. In 1969, the site was submerged in water when a levee protecting it from waters rising behind the then newly constructed Lower Monumental Dam, which was 20 miles (32 km) down the Snake River, failed to hold back water that leaked into the protected area through gravel under the soil, creating Lake Herbert G.