Couple of 20ga slugs in your pocket would have kept you from needing to run back to the truck.
I agree. even if you don't have a tag. Good to have just in case a predator gets to close 

Just be careful if there is a modern firearm deer or elk season open and you don't have a valid bear or cougar tag.
From the hunting regs:
"
10. Hunting during modern firearm deer or elk seasons:You may not hunt wildlife during any modern
firearm deer or elk season, with any firearm
24 caliber or larger or containing slugs or
buckshot for big game, unless you have a valid
license, permit and tag for one of the following:
deer, elk, black bear, cougar, mountain goat,
bighorn sheep, or moose."