Rockwells Mills is the name of a post-office and station of the O & W Railroad about a mile north of Mt. Upton. The name comes from the mills of Chester W. Rockwell which was located there. The settlements of Rockwells Mills and Latham Corners were less than a half mile apart so is treated to some extent as one. The first settlers were Sullivan Reynolds, Robert Mcleod, Lemuel Cornell, John Secor and James Hayes. All came in 1791. Reynolds built a gristmill on the east side of the river.
The hamlet was also called "Union" until 1895 when Urastus Rockwell bought the large mill. Howard Rockwell was the first postmaster in 1874 when the railroad came through.
The mill was burned in 1870 and rebuilt under the name of C.W.Rockwell & Co. The woolen mill was made partly of stone and partly of wood. Part remains today as "The Old Mill Restaurant. Between Rockwells Mills and Latham Corners was a Methodist church whose history dates back to the inception of Methodism in this part of the country.