Built in 1865, the five story frame structure including a mansard roof was the eleventh flour mill built in Eastern Washington and the twenty-first built in Washington Territory. Washington Territory came into being in 1852.

The mill, costing $14,000 was started in 1864 and finished in 1865, was named after the builder Sylvester Wait. He found his perfect location just east of the confluence of the Touchet and Coppei Rivers in what is now southeastern Washington State, but was then Washington Territory.

Large timbers were brought down from the Blue Mountains, from the south in present day Oregon. Some of his equipment came from as far away as San Francisco. Wheat was puchased from surrounding farmers, who found that wheat grew very well on the rolling Palouse Hills and on the flats. Wait sold his wheat by the barrel(196 lbs.) to distant markets, making this a merchant mill.

Waitsburg was originally Wait's Mill, Delta, Horsehead City, Wait's Crossing, and finally Waitsburg in 1868. Waitsburg was platted in 1869 with a pop. of 100, which increased to 250 by 1880. A fire burned much of the town in 1881; but, it was rebuilt and incorporated within the same year. The mill had transferred from Wait to P.A.& W.G. Preston in the early 1870's.

The Waitsburg Historical Society was trying very hard to find the means to preserve the old mill for the last decade and had deeded the property over to the city, where the Waitsburg Community Revitilization Committee had since been working hard to find ways and monies to restore the structure, which had aquired many added buildings since its inception.

By November 2008, a grant had been obtained to repair the roof and engineers reported very little dry rot. Possible plans were for a performing arts center and a museum in the mill when restored. The mill burned in an early Sunday morning comflagration 09/06/09 beginning about 4:14 am. No cause had been determined as of the date of this entry.