The Red River kept its own calendar. A 1987 Paris News column recalled floods in 1884 and 1908 that washed away livestock and farms and changed the river's course. A Denison man named George D. Moulton thought a dam could end that. The Denison Herald, profiling him in 1972 as the "Denison Dam Dreamer," said he came to town as a boy and was raised by his stepfather, Col. J. B. McDougall, a pioneer businessman. On a trip to California in the mid-1920s he heard talk of a Boulder Dam and began thinking about the Red River. By his own account he was "no engineer," but he wrote letters to officials in Washington and, the Herald said, "preached the gospel of Denison." His first known letter, in March 1926, asked Oklahoma Congressman Charles D. Carter for contour maps of the basin.
The lawsuit
Congress authorized Denison Dam in the Flood Control Act of June 28, 1938, at an estimated cost of $54 million. Oklahoma objected. Its governor, Leon Phillips, sued to stop the project, arguing that the lake would flood about 150,000 acres, 100,000 of them in Oklahoma, that about 8,000 people lived in the basin, and that it would take state school land, roads and tax base with it. The Supreme Court ruled against Oklahoma on June 2, 1941. Justice William O. Douglas wrote that flood control on a tributary could be a valid use of the commerce power, because the Red River's floods feed the Mississippi's. The Army's district engineer had estimated that the dam would cut the flow on the lower Mississippi by 35,000 cubic feet per second in a repeat of the 1908 flood.
Moving a valley
Work began in August 1939. The Katy railroad delivered earth-moving equipment on September 22, the first concrete was poured on May 21, 1940, and the Guy F. Atkinson Company of San Francisco finished the embankment on October 18, 1943. German prisoners of war from Rommel's Afrika Korps, held at camps in Tishomingo and Powell, Oklahoma, helped clear land and were paid 80 cents a day in canteen coupons.
The lake took a valley with it. Hagerman and Preston in Texas, and Aylesworth and Woodville in Oklahoma, went under. The Corps of Engineers moved about 3,000 graves from 49 cemeteries and built eleven new ones, and the Katy laid nine miles of new track between Pottsboro and Sadler. Water began to rise on January 6, 1944. At the dedication on July 1, 1944, Sam Rayburn was the principal speaker, and fewer than the 25,000 people expected came. The reservoir was officially named Lake Texoma that year.
Moulton died in Denison on December 14, 1944, about six months after the ceremony and eighteen years after his first letter. When it was finished, the dam was the largest of its type in the country.
A historic exhibit on the lost town of Hagerman stands at Hagerman National Wildlife Refuge, made from land bought for the dam, and the lake spreads below the bluffs of Eisenhower State Park.