I've paddled the entire length of the Snake through Idaho, as well as the Salmon, and never seen a single critter anywhere other than a rattlesnake sunning itself on the rocks. The grizzly population was wiped out before the 1970's. There might be 600 of them left in the entire Yellowstone area... and that encompasses three states... three big states... including Idaho
If you don't have many critters and you aren't worried about coming up on something that's a more than you can handle with your digging spade, more power to you. Where I live there are roughly 1,500 black bears in the small 300 square mile area surrounding my house. I find them on my back deck trying to eat out of my bird feeder from time to time. The first time I saw that I screamed like a little girl and ran one direction while the bear, as scared as I was scrambled off in the other direction.
But the fact is, that while grizzly bears are more aggressive, they are herbivores and won't kill you for food. They'll stand you down and maybe make you climb a tree to keep from getting killed, but they won't eat you, even after they tear you limb from limb. Black bears are less aggressive, but they're omnivores, and they will eat you if they get a chance... every bit of you. A couple of pops out of a loud firearm will drive either one of them away though.
And if you think the most dangerous animal out there is the domestic dog... you have to wait until you see Rover encounter a moutain lion. He'll go running so fast back to whatever hidey hold he can find with his tail tucked between his legs that you won't believe it. Your spade may be the best defensive tool that you think you need, but for me my best defensive tool is lead and gunpowder encased in brass.
I've never had an life threatening encounter with another human, but yes, if it was a life threating situation I'd rather shoot him dead than be buried by his spade.