Celilo Falls
Coordinates: 45°38′58.01″N 120°58′40.53″W / 45.6494472°N 120.9779250°W
Celilo Falls (Wyam, meaning "echo of falling water" or "sound of water upon the rocks," in several native languages) was a tribal fishing area on the Columbia River, just east of the Cascade Mountains, on what is today the border between the U.S. states of Oregon and Washington. 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.
The main waterfall, known variously as Celilo Falls, The Chutes, Great Falls, or Columbia Falls, consisted of three sections: a cataract, called Horseshoe Falls or Tumwater Falls; a deep eddy, the Cul-de-Sac; and the main channel. 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. Frequently more than a mile (1.6 km) in width, the river was squeezed here into a width of only 140 feet (43 m). The seasonal flow of the Columbia changed the height of the falls over the course of a year. At low water the drop was about 20 feet (6.1 m). In 1839, Modeste Demers investigated the area in some detail and described not just one fall but a great many, in different channels and with different qualities. He wrote, "The number and variety [of the channels and falls] are surprising. They are not all equally deep. The falls are from 3 to 12 and 15 feet high." During the spring freshet in June and July, the falls could be completely submerged. The falls were the sixth-largest by volume in the world and were among the largest in North America. Average annual flow was about 190,000 ft³/sec (5380 m³/s), and during periods of high water or flood, as much as 1,240,000 ft³/sec (35,113 m³/s) passed over the falls.
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