Nickel Plate Road No. 639 is a 2-8-2 Mikado type steam locomotive built by the Lima Locomotive Works in December of 1923. It is one of three surviving NKP Mikado type locomotives.
No. 639 was built to handle freight trains over the Nickel Plate Road's former Lake Erie & Western route between Frankfort, IN and Peoria, IL. However, No. 639 did occasionally operate elsewhere on the NKP system. The locomotive was retired in 1957 and moved to a scrap yard in Bellevue, OH.
In 1959, the City of Bloomington, IL, along the Frankfort to Peoria route, requested a locomotive for display. Due to its local connection, No. 639 was chosen for preservation. In the summer of 1959, it was removed from the scrap yard and cosmetically restored at the Nickel Plate's shops in Bellevue. It was moved on its own wheels to Bloomington and arrived in late October. It was loaded onto a truck and taken to a new display track at Miller Park, south of downtown Bloomington, and dedicated on November 1. It remains on static display at Miller Park today.
- Shortly before retirement, No. 639's tender was damaged in a minor derailment and instead of repairing it, the tender was paired with recently retired Mikado type No. 587, and No. 639 got No. 587's original tender. No. 587 was also preserved, and today carries No. 639's original tender and vice-versa.
- In 1996, a bay window caboose from the Southern Pacific Railroad was donated to the City of Bloomington and added to the display with the locomotive.