Tracks reached Colfax in September 1865, and the first trains began running between Colfax and Sacramento on September 4 of that year. Earlier that summer, a teamster camp had been established to support grading and construction activities above Colfax at Long Ravine and Cape Horn. The new railhead town of Colfax became a staging area for construction crews and equipment for much of the following year. Nearby Illinoistown had already been established as the “head of navigation” for freight shipments by wagon and mule to the nearby mines. CPRR built a large freight shed at Colfax to support railroad construction and freight movement to the surrounding area. The railroad also commissioned the building and operation of a passenger depot and eating house next to the freight shed, at what was then the Depot St. crossing.
Shortly after the Nevada County Narrow Gauge Railroad began service from Colfax to the Grass Valley/Nevada City mines, a new freight depot was constructed to replace the original freight shed. This freight depot included a covered platform to transfer goods from CPRR to NCNG cars.
In order to access the transfer platform, NCNG freight cars had to be shuttled across the CPRR mainline, creating rail congestion along with freight wagon congestion on the town’s Main Street. In 1905 the freight depot was relocated across the tracks and NCNG freight cars no longer had to cross the mainline. A new passenger depot was also built in 1905, which still exists as the present-day Colfax depot on Railroad Ave.
One more major change was yet to come. In 1910-1915, new parent company Southern Pacific added a second track to the line between Rocklin and Colfax and created a major yard and engine house at Colfax. This required removal of two large hillsides, and realignment of the tracks to eliminate the lazy-S pattern through town. An additional result of this new alignment was the need to move the freight depot one more time, to its current location on the Main Street side of the tracks.