Renewed mention of the Holt 5 Ton brought me back to this picture. According to the caption, this is Tractor-drawn Artillery of 89th Division, before the largest hangar in Germany.
I've established the following:
The 89th were in action on November 11th, at Stenay, north-west of Verdun. It was, apparently, the last town captured on the Western Front. In December, the American Third Army crossed into Germany and took up station in the northern sector of the Koblenz bridgehead, with its HQ at Montabaur, a few miles to the east of Koblenz. The nearest Zeppelin bases were at Düsseldorf and Düren, to the north-west. Assuming that the claim about the biggest shed is correct, that would tell us where the pic was taken. I haven't yet found anything about which was the biggest shed.
"Sometimes things that are not true are included in Wikipedia. While at first glance that may appear like a very great problem for Wikipedia, in reality is it not. In fact, it's a good thing." - Wikipedia.
My guess would be: Köln-Wahn, the Wahner Heide was a shooting range of the foot artillery, but there also were Zeppelin facilities. Note, however, it's only a guess, at the moment. I've seen that hangar before, I only need to find the pictures...
