Don W. Phillips ran a small milling facility at or near Conroe during the 1950s and 1960s. He bought it from Longhorn Lumber Company, belonging to James O. Phillips, in 1954, its sawmill and the lumber on its yard. The next year, Phillips bought out Tom Branch Lumber Company's planing facility located three and a half miles southeast of Conroe, which included a five-acre tract, five tenant houses, wagons, a tractor, a boiler, a steam engine, two circular saws, and a planing mill with a planer, blower, cutoff saw, and a trimmer.
The Directory of Texas Manufacturers 1956-1958 reported that the Don Phillips Lumber Company was established as a sole proprietorship in 1955, employing less than fifty workers. It was located on Highway 75 South.
The Don W. Phillips Lumber Company was listed in the 1957 and 1966 editions of Nelson Samson's Directory of Wood-Using and Related Industries in East Texas. He was on the 1968 address list of the Southern Pine Inspection Board.