I was there on August 2 on my way to Glenwood Springs and ultimately Denver and Red Rocks Amphitheater. In response to your inquiry, Wikipedia states: "Until 1992 Amtrak used the ex-Denver and Rio Grande Western Railroad (D&RGW) station, constructed in 1906, located next door to the current building (according to "Great American Stations: Grand Junction, CO). The current station building was built in the late 1970s and originally used as a restaurant." The current building is ding-bat architecture. The other building to the east that I believe you are referring to which says "Union Station" on top says DRGW Station Master or something like that on trackside. I'll check my photo for exact wording. Others probably know more.