The Dalles Lock and Dam (The Dalles Dam) is one of the 10 largest producers of hydroelectric power in the United States. Since its first generator went online in 1957, the dam has produced more than 9.2 billion kilowatt hours of electricity. Today [2021], its 22 generators in its 2,089-foot-long powerhouse produce enough electricity to power 800,000 homes. The dam is the second of eight on the Columbia-Snake Inland Waterway, a 465-mile river highway that allows barge transport of cargo between the Pacific Ocean and Lewiston, Idaho. Located east of The Dalles, Oregon, it stretches nearly a mile and a half across the Columbia River and the Oregon-Washington state line, forming Lake Celilo behind it.
Beginnings
For millennia the Columbia River has been a lifeline for the indigenous people of the Northwest, providing both sustenance and a route to the ocean and the interior mountains. When early American explorers Meriwether Lewis (1774-1809) and William Clark (1770-1838) passed through the Northwest in the early nineteenth century, they followed the final 325 miles of the river from its intersection with the Snake River to the Pacific Ocean; other explorers, fur traders, and a few early non-Native settlers followed it too. During the early nineteenth century, the French name Dalles became associated with dangerous rapids along the river which ran through narrow and rocky channels above the site where the dam would later be built. The rapids subsequently became known as the Long Narrows (and were also called Fivemile Rapids).
As non-Native development continued to spread throughout the Pacific Northwest in the late nineteenth century, demand increased to improve navigation on the impassable stretches of the Columbia River. The 1896 opening of the Cascade Locks and Canal roughly 40 miles west of The Dalles allowed upstream steamboat traffic to travel as far east as The Dalles, where the rapids east of the city prevented further travel (though, in the right conditions, empty, shallow-draft vessels could make it to Celilo Falls). In 1905 construction began on the Dalles-Celilo Canal, an eight-and-a-half mile, 65-foot-wide channel (with five locks) that ran to the head of Celilo Falls. When the canal was completed in 1915, river traffic could travel as far east as Lewiston, Idaho, along the Columbia River and its main tributary, the Snake River.
The Columbia River wasn't just an aquatic highway. Its rapid flow and high-water volume had excellent potential to generate hydroelectric power. To do this, it would be necessary to build dams to harness this power. The dams would also provide additional benefits, creating reservoirs for irrigation and recreation, and aiding with flood control. Equally as significant, the dams would benefit navigation, eliminating narrow channels along the river and creating slack-water pools.
Planning
Legislation passed during the 1920s provided the necessary authority for the U.S. Army Corps of Engineers (Corps) to begin planning for dam construction on the Columbia River and on other rivers in the United States. The Federal Water Power Act (usually referred to as the Federal Power Act) of 1920 focused on providing a comprehensive national plan to promote and regulate the competing interests of water usage that would be generated from the dams, such as navigation, irrigation, flood control, and hydroelectric power. The River and Harbor Act of 1925 asked the Corps to estimate the costs of developing hydropower on American rivers, while the River and Harbor Act of 1927 authorized the Corps to conduct surveys of the Columbia River for potential dam sites.
In July 1931, Colonel Gustav Lukesh (1878-1949), division engineer for the Corps Portland District, submitted recommendations based on these surveys to his superiors for a series of dams on the Columbia River. Based on his recommendations, the Corps submitted the proposal to Congress that autumn. The plan proposed a total of eight dams on the Columbia River, with two dams on the mid-Columbia River, an area which today includes not only The Dalles Dam but also the Bonneville, John Day, and McNary Dams. The plan -- referred to by the Corps as "Series D" -- proposed a dam at Cascade Rapids, which became Bonneville Dam. The plan further proposed a larger, multiple-arch dam to be located at The Dalles. It called for the dam to reach 330 feet above sea level and extend for nearly four miles, forming a massive, 154-mile lake stretching as far east as the Snake River and then extending another 15 miles upriver on the Snake.
Though the mammoth dam would have generated an enormous amount of power, there wasn't yet the need for it; in the early 1930s, many rural areas still didn't have electricity. In 1934, the Corps dropped the plan for a large dam and instead proposed an alternate plan that called for a smaller dam at The Dalles, as well as other dams on the mid-Columbia River. Construction of the Bonneville Dam, located 45 miles west of The Dalles, began that same year and was completed in 1938. The advent of World War II in Europe the following year (and in America two years later) delayed construction of other mid-Columbia River dams. In 1947, two years after the end of the war, construction began on the McNary Dam near Umatilla, about 100 miles upstream from The Dalles.
At this point, there were still no firm plans for the construction of The Dalles Dam. That changed in 1948, when heavy snow runoff from the mountains, combined with heavy rain during the late spring, caused one of the most financially devastating floods in the Columbia River's history. The Bonneville Dam wasn't enough to handle the flood, and the McNary Dam was years away from completion. This pushed planning for more dams into high gear. Working with the Bonneville Power Administration and the Bureau of Reclamation, the Corps completed a detailed plan designed for power generation, navigation, flood control, and other purposes on the Columbia River and its tributaries. Congress published this plan as House Document 531 in March 1950. Two months later, Congress passed The River and Harbor Act of 1950. It included a second section, commonly cited as the Flood Control Act of 1950, which authorized and appropriated funds for a wide range of public works projects nationwide, including The Dalles Dam.
Construction
Formal ceremonies marking the start of construction took place on a sunny March 13, 1952, though some preliminary excavation work began a few weeks earlier. "The whole city of The Dalles turned out to see the sight," recounted The Seattle Times the next day ("Explosions Mark…"). Schools and businesses were closed, a parade led thousands to the river to witness the ceremonial groundbreaking, and spectators stopped their cars along Highway 30 on the Oregon side of the river to watch the spectacle. Six tons of dynamite were set off along the river's north shore in Washington to loosen rock at the site of the dam's northern abutment, catapulting enormous columns of water and dirt more than 100 feet into the air.
Construction giant Guy F. Atkinson Company entered into a joint venture with Ostrander Construction Company to build the dam, with the work broken down into seven individual contracts for construction of the spillway, the navigation lock, the powerhouse, and other components of the dam. A temporary cofferdam, designed to hold back water during construction, was completed by late summer 1953, and excavation for the powerhouse was completed by this time as well. In December, the first concrete was poured for the spillway and the powerhouse. Work on the navigation lock began in September 1954, and construction proceeded so smoothly that during 1955 parts of the project ran ahead of schedule.
The powerhouse's initial substructure was completed in January 1956 and had room to house 14 generators. A second substructure, consisting of empty bays for an additional eight generators to be added as needed, was completed in June of that year. By March 1957 the project was roughly 75 percent complete, and enough work had been done to close the dam's gates. A celebratory event to lower the gates for the first time took place on March 10, 1957. At 10 a.m. the gates were closed and a brand-new, 24-mile-long lake, Lake Celilo, formed behind the dam within hours. Two major television stations, KGW from Portland and KING from Seattle, covered the occasion in impressive detail, and an estimated 10,000 people dropped by at varying times during the day to watch the lake's formation. At the same time, they witnessed the disappearance of the Big Eddy (a large, dangerous whirlpool located at the western end of the Long Narrows just above the dam), the Long Narrows, and Celilo Falls several miles beyond that.
The Columbia River from The Dalles through the Long Narrows to Celilo Falls had been a primary fishing ground for Native Americans for at least 10,000 years. Numerous tribes gathered there in the spring and summer to fish and trade, and when William Clark passed through the area in 1806, he described the Long Narrows as "the great mart" ("Celilo Falls…"). The tribes retained their fishing rights at their usual and accustomed places at the falls and rapids when they ceded the land by treaty to the United States in 1855, and they were not eager to see these rights drowned by the lake's creation. The U.S. government eventually negotiated a $26.8 million settlement with several tribes for the loss of their fishing grounds that followed from the formation of Lake Celilo. The government also built a new village near the site of the former Native village that was obliterated by the lake, and in the mid-2000s Congress allocated additional funds to rebuild the village. This work was largely completed by 2019.
The dam's navigation lock opened a week after the gates were closed, and barge traffic resumed on the river. Though numerous sources list the dam's completion date as March 1957, additional work remained to be done. For example, none of the powerhouse's generators had been installed, and the powerhouse structure above ground was still not finished. Nevertheless, one small generator went online in May, but produced less than 20 percent of the power of the larger generators that were planned. The first regular generator, capable of producing 78,000 kilowatts of power, went online on September 25, 1957, followed by the second generator on Halloween. Two more generators were added before the first section of the powerhouse (which would house the dam's first 14 generators) was completed in September 1958.
By this time construction was 90 percent complete, and most of the remaining work was minor. Much of it included adding roadways, fencing, and lighting, and this was accomplished during 1959. At the same time, the Corps continued adding generators to the powerhouse every few months. Vice President Richard Nixon (1913-1994) took the honors of activating the 10th generator when he dedicated the dam in a ceremony on October 10, 1959, and the 14th generator began operation a year later, on October 28, 1960. The total cost of construction was approximately $286 million (more than $2.5 billion in 2021), and accidents claimed 16 lives during construction.
The Dalles Dam
The top of the dam is 291 feet above sea level (183 feet above the riverbed), and the average pool elevation at the dam is 158 feet. The entire dam structure -- including the spillway, powerhouse, and embankments -- measures 7,365 feet. The dam has been described as shaped like the letter L, and using this analogy, the powerhouse is located on the long part of the L, on the part of the structure which runs parallel to the river, while the spillway runs across the river. This was a singular design not used for any other Columbia River dam, and it was chosen because it allowed for a longer powerhouse (and accordingly more generators) than would have been possible had the powerhouse been built directly across the river.
The Oregon-Washington state line follows the flow of the river's original channel, which runs near the Oregon shore at the dam location. Accordingly, most of the dam lies in the state of Washington, while the visitor's center is in Oregon. From the Oregon side, the dam begins next to Patterson Park, then crosses into Washington while making a curve until it is parallel with the river. The 2,089-foot-long powerhouse is located here. Past the powerhouse, the dam makes a 90-degree turn to form the spillway section. The navigation lock is located at the northern end of the dam, adjacent to the Washington shoreline.
By the late 1960s, the Corps realized that the region's energy needs were increasing faster than anticipated. In 1969, work began on modifying the empty bays in the powerhouse in order to install the additional eight generators which had been planned. The newer generators were more powerful than the original 14 generators, with each generator capable of producing 86,000 kilowatts. They were installed in 1972 and 1973, with the final generator going online in October 1973. (A 265-ton emergency crane also was added in 1973 to support the original forebay crane. These cranes provide backup support to the generators in case of an emergency.) The power generated is routed to the Big Eddy substation (named after the large whirlpool submerged by the lake) on the Washington side of the dam for transmission throughout the Northwest.
The spillway measures 1,447 feet long and has 23 radial gates. Radial gates, also known as tainter gates, consist of a convex skinplate reinforced by horizontal support beams, while vertical beams on the gates transfer the water pressure to two radial arms located on either side of the gate. Each gate is 50 feet wide, 42.5 feet high, and weighs 70 tons. The spillway is designed to handle a flood up to 2.29 million cubic feet (17.13 million gallons) of water passing through each second.
The lock is a concrete-lined channel, 675 feet long and 86 feet wide, with guide walls extending from both of its ends. Approximately 10 million tons of cargo, mostly grain and petroleum products, pass through it each year. Its normal lift is 87.5 feet, though it's capable of handling a lift of up to 90 feet. It normally takes 20 minutes to fill and empty the lock, and approximately half an hour for ships to pass through. Gates measuring 106 feet long and 54 feet wide are installed on both ends of the lock, and an operator's shack is located along the lock wall.
The fish passage system at the dam includes two fish ladders for upstream fish migration, known respectively as the North Ladder and the East Ladder. The North Ladder is located where the dam joins the Washington shoreline, and is 1,761 feet long and 24 feet wide. The East Ladder is located at the powerhouse's eastern end, and measures 1,801 feet long and 30 feet wide. Both passages are 6 to 8 feet deep, and the speed of water flow through them can be regulated; for instance, the flow is maintained at a slower rate during peak salmon season. Two small generators called fish units are dedicated to the fish ladders in order to maintain water flow through the passages. Additionally, the dam's ice and trash sluiceway is open between March 1 and December 15 for use as a surface passage route for downstream juvenile salmon and kelt steelhead.
Parks and Recreation
Besides authorizing the construction of The Dalles Dam, the Flood Control Act of 1950 authorized the Corps to build and operate recreational facilities. Around 1970, the Corps added several small parks at the dam. The best known is Seufert Park, which runs along the Oregon shore at the visitor's center. The name comes from a large fish cannery originally on the site. Patterson Park is a small park also located on the Oregon shore near the East Ladder of the dam. Westrick Park is a similarly small park that runs along the southern end of the structure itself from the western end of the powerhouse to where the dam turns to cross the river. (Due to public safety and security concerns, both Patterson and Westrick parks are currently [2021] closed to the public.) The North Shore Park is located adjacent to the North Ladder on the Washington side of the dam and offers visitors views of the navigation lock and access to a boat ramp.
The Corps sought other ways to connect visitors to the dam during the early 1970s. In 1973, it began giving train tours originating at Seufert Park. The three-car train, which was painted red, white, and blue in 1976 in honor of America's bicentennial, provided tours to the powerhouse and continued as far as Westrick Park. The tour was quite popular in its day, and the little railroad even had its own name: Les Dalles Portage Railroad. In 1981, the Corps added a depot at Seufert Park for the train. Increased security concerns after the 9/11 terrorist attacks and deteriorating rails led to the end of the rail tour in 2005, and the depot was subsequently converted into the visitor's center.
This was not the end of the tours, though. The Corps continues to provide ranger-led educational tours of the dam. In 2019, bus tours were offered during the summer months twice a day each Saturday. They started at the visitor's center, which now serves as an educational center about the dam and its history. Live cameras let visitors watch fish swimming through the East Ladder, and visitors can also enjoy a 250-gallon native fish aquarium, interpretive exhibits, and a film about The Dalles Dam. Outside of the visitor's center there is a covered picnic shelter and access to trails.
