The "A" on the stock yard building in the background suggests the photo is cropped from a NP Joint Facilities Book. The date of 8-28 in the lower right corner is consistent with the period the books were prepared. I believe there may be a copy of the volume covering the Billings joint facilities at the railway museum in Duluth. The facility would have been documented if it was owned by the NP but shared under a joint facilities agreement with the CB&Q and/or GN.
I don't believe the Jt. Fac. volumes at Pacific Northwest Railway Archive include Billings.
