 It was housed in several farm houses northwest of the current town site of Thorp until 1884, when it was re-established at the Thorp gristmill through the instrumentality of James L. Mills, who named it "Oren" after Oren Hutchinson.In 1889, the name of the post office was changed to "Thorp" to conform with the name used for the settlement by the Northern Pacific Railroad, and, in 1895, the post office was moved just down the road to the location of the depot that was built there and the town site that had been platted around it.It was the system of water delivery that made the mills at Thorp possible, and the farming lands around Thorp are the oldest irrigated section in Kittitas County.