It's in Colorado. I forget where (don't have it on me right now).
Just cuz you gotta draw the line somewhere, I usually draw the line at folders (these are envelope-like folders of postcard images on gatefolding paper; most popular in the '30s & '40s, I reckon). But I got a few in a bulk box and just recently opened 'em up to examine. Score! How did that Denver folder know to surprise me with a "roadside" card??