This locomotive was built by General Motors Electro-Motive Division in April 1959 as Chicago Burlington & Quincy subsidiary Colorado & Southern SD9 837.
In 1970 the new railroad Burlington Northern was created upon the merger of the CB&Q (and parent company of the C&S), Great Northern, Northern Pacific and Spokane Portland & Seattle. While most of these locomotives acquired a new identity (BN) and, often, a new number. However, initially the BN retained the C&S (and also the other subsidiary, Fort Worth & Denver) reporting marks, so even if it had received Cascade Green paint, it retained the CS reporting mark, but acquired a new number: CS 6232.
By 1977 or 1978 (the exact date is a bit unclear) the BN bailed on those CS and FWD reporting marks, becoming BN 6232.
In 1995, yet another merger caused it to acquire yet another identity: Burlington Northern Santa Fe 6129 (although it wasn't renumbered until early 1998).
BNSF 6129 was retired in 2003 or 2004, and it was sold to Ag Processing, becoming AGPX 6129.
By September 2012 (the first time I saw this unit) it had become DeBruce Grain 6129 and assigned to the grain elevator in Benkelman NE.
