Common enough to be aware, but not common enough to be of concern, IMO. Likely to see more driving than in the field. Bites of dogs can happen though. I'd know where the closest vet is and have their # programmed into your phone. If you're the precautious type you could ask your vet to give you a syringe full of benedryl and tote it around with you (I've done that). You could also give your dog the Red Rock vaccine before you go, but be mindful if bit the vet will still administer a pretty expensive anti-venom, so I'm not really sure what it's buying you, maybe a reduced risk of death. In 6 or so years of hunting Montana more than week each year, multiple guys, as many as 21 dogs on a trip (that's a lot of dog*miles!), we've never had one bit. But I know people who have had dogs bit, and have heard of dogs dying. You could reduce risk by staying away from prairie dog towns and rocky outcroppings.