For these “citizen scientists” and researchers, Bigfoot is very real. So, each year they confer on more controversial questions, like how to capture the elusive creature and whether it’s ethical to kill one. Marc DeWerth’s encounter with the creature was sudden, terrifying and beautiful. He can recall the events of that afternoon down to the minute. It was April 20, 1997. DeWerth was a mile-and-a-half deep in the forests of Coshocton County, Ohio, investigating what he had been told was an interesting collection of beaver dens. Though he never found them, DeWerth had a satisfactory day in the woods, and...