The Alaska Railroad built a branch line to the Chickaloon coal mines in 1916 with a stop in the town of Palmer. The railroad depot was not built until 1935, however, when hundreds of colonists were scheduled to descend on the Matanuska-Susitna valleys, disembarking at Palmer.
The original building was about 94 feet long, wood-framed and gable-roofed. The portion with the higher roofline was the warehouse, originally 28 feet long; it was extended to its full length of 84 feet in 1948. The shorter portion, about 66 feet long, housed the ticket office and waiting room on the track side and the agent's living quarters on the other side. At the end, an entrance half the width of the depot was also covered with a gable roof. It originally had open sides, but was enclosed in 1948. The building has a new metal roof and cornice and is covered with narrow clapboards.