In 2007, Don Briggs, a physical education professor at the University of Northern Iowa (UNI), knocked on the door of Rusty Leymaster, a farmer with about 400 acres and a silo just west of Cedar Falls.

“This guy just shows up and said he wants to put ice on our silo and climb it. My daughter said: ‘Yeah, that sounds like fun.’ I guess you could say it’s been all downhill since then,” said Leymaster.

Briggs, an outdoor recreation specialist and avid climber, was...