The Chehalis Western Railroad (reporting mark CWWR) was the name of two different shortline railroads that were owned and operated by Weyerhaeuser between 1936 and 1993. The first Chehalis Western, which existed from 1936 until 1975, was a shortline Class III railroad operating in Washington state, while the second one, which existed from 1981 until 1993, was a private railroad that operated on a different set of lines that Weyerhaeuser had later acquired.
In 1936, Weyerhaeuser incorporated the Chehalis Western Railroad as a publicly regulated, common-carrier shortline to carry lumber and forest products over a 10-mile stretch of track from Chehalis, Washington to Ruth, Washington that Weyerhaeuser had purchased from the Chicago, Milwaukee, St. Paul and Pacific Railroad, also known as the Milwaukee Road. The Chehalis Western also operated on trackage rights over the Milwaukee Road from Chehalis to Western Junction, where the trains would join a Weyerhaeuser-owned logging line (known as the "Vail" line) that would go north to a log dump at South Bay, Washington. And Chehalis Western trains also operated on trackage rights over the Northern Pacific Railroad from Pe Ell, Washington to Milburn, Washington.
On December 1, 1975, Weyerhaeuser reorganized the railroad under a new name, the Curtis, Milburn & Eastern Railroad. The CM&E stopped operating on the trackage rights between Pe Ell and Milburn, and the line only operated between Chehalis and Curtis, Washington. The CM&E stopped operating in 1980 and was formally abandoned in February 1993.
The Chehalis Western Railroad name was resurrected in 1980, when the Milwaukee Road abandoned all of its trackage west of Miles City, Montana. At that point, Weyerhaeuser acquired all of the Milwaukee Road's trackage south of Tacoma, Washington, except for some trackage rights. The lines that Weyerhaeuser purchased measured <23 miles long and were the Milwaukee Road's routes from Tacoma to Chehalis and from Frederickson, Washington to Morton, Washington. In order to service the new lines, Weyerhaeuser purchased four brand-new EMD GP38-2 locomotives.