UPDATE: Another postcard with this image is back on eBay.
(08/01/2015) You can learn more about Fantastic Caverns here: http://www.ewillys.com/2012/11/22/bill-visits-the-fantastic-caverns/
“Springfield Missouri~Jeep & Tram Thru Fantastic Caverns~1960s Postcard”
I believe that this jeep is sitting in the lobby at Fantastic caverns. They have always used jeeps and upgraded with model changes. I doubt they used every model, but I know they had the 2A, a 5 a 7 and a Wrangler.
I’ll bet the jeep exhaust did wonders for the formations.