The name refers to a series of cascades and waterfalls on the river, as well as to the native settlements and trading villages that existed there in various configurations for 15,000 years.

Celilo was the oldest continuously inhabited community on the North American continent until 1957, when the falls and nearby settlements were submerged by the construction of The Dalles Dam.

[5] These features were formed by the Columbia River's relentless push through basalt narrows on the final leg of its journey to the Pacific Ocean.

[5] Celilo Falls itself was the first in a series of cascades and rapids known collectively as The Narrows or The Dalles, stretching for about 12 miles (19 km) downstream.

[4] Fur trader Alexander Ross wrote, "[The water] rushes with great impetuosity; the foaming surges dash through the rocks with terrific violence; no craft, either large or small, can venture there safely.

[10] They built wooden platforms out over the water and caught salmon with dipnets and long spears on poles as the fish swam up through the rapids and jumped over the falls.

[11] Historically, an estimated fifteen to twenty million salmon passed through the falls every year, making it among the greatest fishing sites in North America.

[12] Celilo Falls and The Dalles were strategically located at the border between Chinookan and Sahaptian speaking peoples and served as the center of an extensive trading network across the Pacific Plateau.

[13] Artifacts from the original village site at Celilo suggest that trade goods came from as far away as the Great Plains, Southwestern United States, and Alaska.

[15] When the Lewis and Clark Expedition passed through the area in 1805, the explorers found a "great emporium...where all the neighboring nations assemble," and a population density unlike anything they had seen on their journey.

"[18] The seasonal changes in the Columbia's flow, high in summer and low in winter, affected Celilo Falls dramatically.

[23] The volume of water at Celilo Falls made The Dalles an attractive site for a new dam in the eyes of the Corps of Engineers.

In 1947, the federal government convened Congressional hearings and concluded that the proposed dam at The Dalles would not violate tribal fishing rights under the treaties.

[27] Subsequently, the government reached a monetary settlement with the affected tribes, paying $26.8 million for the loss of Celilo and other fishing sites on the Columbia.

A small Native American community exists today at nearby Celilo Village, on a bluff overlooking the former location of the falls.

The survey revealed that the falls remain intact below the artificial lake, and that "rocky outcrops, carved basins and channels that match aerial photographs from the 1940s.

[3] In response, Northwest RiverPartners issued a statement that the dam remains important for hydropower electricity generation for ports and businesses in the area.