Remember the big draw for narrow gauge model railroaders is layouts, layouts and more layouts. Real steam trains in backyard or nearby is a plus. Facilities might be great for a convention and hotel space in Alamosa. However if their is no local organizing committee for the convention, then someone outside the area will have to do all the footwork. The upcoming NNGC in Maine is one of the challenges for organizers.
Past NNGC have been in Durango, Colorado Springs and Denver. All had excellent conventions. Durango has only a few model railroads, but the location was great.
Dale Brown