In May 1865, Sylvester M. Wait (d. 1891) begins operating a flour mill in the midst of farmland clustered around the convergence of the Touchet River and Coppei Creek in Walla Walla County. The previous year Wait had met Dennis Willard, an early settler in the Touchet Valley, who was in Lewiston, Idaho, selling supplies to miners. Wait returned with Willard and, on land donated by Willard and William Perry Bruce, set up a mill to process local wheat into flour. The town of Waitsburg will grow up around the mill, which will continue to expand and operate under different owners until it is closed 92 years later.
In 1859, a number of settlers began farming around the juncture of the Touchet River and Coppei Creek in the Touchet Valley. After a few years of farming along the rivers, some of these pioneer farmers began dryland farming on the slopes surrounding the valley and started to produce significant quantities of wheat. In 1864, while selling supplies to miners in Lewiston, Dennis Willard, who owned 160 acres in the Touchet Valley, met Sylvester Wait. Originally from Waitsfield, Vermont, Wait had previously operated a flour mill in Rogue River, Oregon, until hostilities there had forced him to abandon his business. He then opened a dairy in Lewiston. Willard persuaded Wait that the Touchet Valley, where ample wheat was grown and the rivers were powerful, was an opportune site for a flour mill. Moreover, Willard informed Wait, there were some 5,000 bushels of wheat ready to be shipped to Walla Walla. There would be more profit in grinding this wheat into flour and packing it to the mines.
Willard and Bruce donated about 10 acres of land on the north side of the Touchet River for a mill and a residence for Wait and his men. They granted Wait rights for the millrace, and the other farmers in the area held their grain until the mill was in operation. Wait secured investment capital totaling about $14,000 and traveled to San Francisco for the necessary supplies. A two-story, 40-by-50-feet wood-frame structure, assembled with whatever wood could be obtained from the surrounding area, was built and one set of small millstones was installed. In May 1865, the mill went into operation and flour was soon en route to mining camps in Idaho.
A town, which came to be known as Waitsburg, quickly developed around Wait's mill. In 1866, Wait sold half of his interest in the mill to brothers William (1832-1916) and Platt Preston and the operation was enlarged. In 1870, Wait sold his remaining interest in the mill to the Preston brothers and moved upriver to build another mill in the new town of Dayton. The Preston brothers further expanded the Waitsburg mill and installed more and larger millstones. Later, the millstones were replaced with steel roller machines. Both the mill and the town grew, especially after a rail line connected Waitsburg with the regional and national railway network. In 1891, Frank Parton of Albany, Oregon, purchased a one-third interest in the mill, which then operated under the ownership of the Preston-Parton Milling Company. By the turn of the century, the five-story plant was producing some 400 barrels a day of fine and even white flour.
In 1911, William B. Shaffer, who had become general manager of the mill in 1886, bought Parton's interest and the Preston-Shaffer Milling Company was incorporated. The company expanded in the early twentieth century, establishing mills in Athena and Milton, Oregon, and in 1936 the Waitsburg mill was converted from water to electric power. In 1957, Preston-Shaffer stockholders voted to discontinue the business and the Waitsburg mill was closed. In September 2009 the abandoned mill, which had been on the Washington Trust for Historic Preservation's endangered property list since 2005, was destroyed in a fire.