The Standard Coal Company was located on the Denver & Rio Grande's Spring Canyon Branch in Standardville Utah. As the name indicates, it was a "standard city," one of the first built to a master plan, one of the most modern and technologically advanced towns in the entire country, incredible considering it was a coal company town. The foundations for the tipple still stand and are impressive.
This is all standard gauge. The Utah lines were standard gauged in 1889-1891. After that, there was not one single foot of narrow gauge track operated by the Rio Grande anywhere in the state, so chances are if you see a picture in this group taken in Utah the question "is this narrow gauge?" is moot.
Others have covered the hows and whys of this style of Ottumwa boxcar loader. A while back commodities shipped in stock cars were discussed. Stock cars also carried coal and there are many photos of stock cars positioned at the tipples of the Carbon County (Utah) coal fields of which this photo is a part of. This loader tipped the car up, a conveyor filled the end of the car to the door, then they placed temporary bulkheads against that load and tipped the car the other way and did the same on the opposite end. Unloading was done with good old fashioned shovels and muscle, since most coal yards that received these boxcars didn't have an unloading machine to reverse the process.
On the subject of winter supplies - coal mines don't shut down when it snows. Perhaps dealers did stock up in the fall, but the mines are still running 24 hours a day, seven days a week. They're not piling that coal at the mine portal, they absolutely must have sufficient cars at all times to handle 100% of their output every single day. This was a struggle for the D&RG to meet those requirements, which is partially why the Utah Railway was organized and constructed a parallel mainline once the mine companies were fed up with the inability of the D&RG to satisfy the demand for timely shipment. Thus, coal was being shipped all year long, especially during Utah's wet winters when slushy snow falls in the desert and freezes overnight, turning any open loads into solid blocks of ice which is still a problem today.