I managed to find one photo of the Carbonera Coaling Station, on e-bay, and Ben's model seems correct. Including the low beam across the track closer to the mine entrance. I would speculate that this was not a through track but rather a siding on which gondolas were loaded and stored. Locomotives were probably restricted to the outer track except when moving cars on the siding. Locomotive coaling was probably only done on the outer track. In fact, judging from the photo, there wasn't clearance for even a caboose or high sided gondola.
Edit: Found a public domain version of the photo;
Caption: Tipple of Gilson Asphaltum Company's Carbonera mines. Garfield County, Colorado. 1927. - ID. Erdmann, CE 276 - ece00276 - US Geological Survey - Public domain image File
Note that in the ebay version it is obvious that, as in Ben's version, the chute for the inner track is lower for filling gondolas and the outer chute is higher for filling tenders.