We've got large numbers of lions here in N ID but no poisonous snakes. I'll take the lions anytime over the snakes. Anytime I've hunted early season chukars/huns in S ID, I've been on edge, knowing I could bump into a snake anytime.
A few years back, hunting Brownlee my friend and I pulled over in a wide spot on the road. We were planning on walking up a tight little canyon down the road a couple of hundred yards but as we were getting our gear organized a 4 wheeler with a dog box strapped on, pulled into the canyon entrance and the guy headed up the canyon. We stood there are few moments deciding where we would go when a shot rang out. Shortly the guy came out and said he'd just blasted a rattlesnake and due to the tightness of the canyon didn't want to entertain the chance of bumping another snake, particularly with his dog.
Since the guy didn't hunt the canyon, my friend decided we should give it a try. I walked in as far as where the rattlesnake had been shot(laying along the trail), looked at the tightness of the canyon and told him I'd wait at the vehicle for him.