Marmes Rockshelter

Marmes Rockshelter is a deeply stratified archaeological site located at the confluence of the Palouse River and the Snake River in Franklin County, Washington. The site, excavated in the 1960s, yielded some of the oldest and most significant evidence of early human occupation in the Pacific Northwest, including ancient human remains and a rich assemblage of artifacts. Its discovery and subsequent flooding became a pivotal event in North American archaeology and cultural resource management, highlighting conflicts between archaeological preservation and federal water projects.

Discovery and excavation

The site was brought to scientific attention in 1952 by local rancher Roland Marmes, for whom it is named. Formal archaeological investigation began a decade later under the direction of Washington State University archaeologist Richard Daugherty, in collaboration with geologist Roald Fryxell. Initial test pits in 1962 revealed extraordinary depth and preservation, prompting major excavations funded by the National Science Foundation. The work intensified in 1968 when human bone fragments were unearthed from deep strata, leading to a high-profile, federally funded salvage operation as the impending completion of the Lower Monumental Dam threatened to inundate the site.

Archaeological significance

Marmes Rockshelter gained immediate national significance for providing the first clear evidence of human occupation in the Columbia Plateau region dating back over 10,000 years. The site's exceptional organic preservation, due to a protective layer of volcanic ash from the eruption of Mount Mazama, offered an unprecedented window into early Holocene lifeways. Its findings challenged previous models of the Pebble Tool Tradition and provided critical data on the transition from Paleo-Indian big-game hunters to more diversified Archaic foragers. The controversy surrounding its flooding also spurred major changes in federal policy, influencing the development of the National Historic Preservation Act.

Stratigraphy and dating

The shelter's deposits exceeded 40 feet in depth, containing a continuous sequence of human occupation layers sealed by distinctive volcanic tephra. The key marker was a layer of ash from the circa 5,600 BCE eruption of Mount Mazama, which created Crater Lake. Stratigraphy below this ash dated human activity to the early Holocene. Radiocarbon dating of materials like bison bone, camas bulbs, and woven fabric placed the earliest human use at approximately 10,000 years before present. This chronology was corroborated by tephrochronology and geomorphology studies conducted by Roald Fryxell, firmly establishing the site's importance for understanding the peopling of the Americas.

Human remains and artifacts

The most famous discovery was a collection of cremated and inhumed human bones, known as the Marmes Man remains, dating to around 9,000 years ago. These represent some of the oldest human remains found in North America at the time. The artifact assemblage was remarkably diverse and well-preserved, including projectile points of the Cascade point type, bone needles, awls, and fragments of the oldest known textiles in the Americas. Faunal remains indicated a diet rich in bison, deer, elk, and freshwater mussels from the Snake River, while perishable items like woven mats and cordage provided unique insights into early technology.

Site preservation and flooding

Despite a massive emergency salvage project and the construction of a protective coffer dam by the U.S. Army Corps of Engineers, the site was catastrophically flooded in 1969 by the reservoir of Lower Monumental Dam, Lake Herbert G. West. The flooding occurred before excavations were complete and submerged much of the unexcavated deposits. The event generated significant public outcry and political debate, directly contributing to the strengthening of archaeological safeguards within the federal government. A portion of the salvaged collection is curated by the Washington State University Museum of Anthropology, while the site itself remains under the waters of the reservoir.

Category:Archaeological sites in Washington (state) Category:Archaeological sites on the National Register of Historic Places in Washington (state) Category:Franklin County, Washington Category:Flooded towns in the United States