We were using that term in the mid 80's when I was working at Yellowstone.

Funny story:
I was making my way across the grounds at Lake Yellowstone (on my way to work) when I saw a van parked out in the middle of a field full of grazing bison. The driver had gotten out and was standing 20yrds away from his vehicle, taking pictures.

Before I could even yell out a warning, a bull decided that he was sick of the paparazzi and began to charge. You've never seen an overweight, middle-aged touron move so fast!

He managed to climb into the cab, but the beast still head-butted the hell out of his fancy camper!