In the park or in close proximity, grizzly bears are a fact in many areas of Montana, Idaho and Wyoming as well as Canada and of course Alaska. My daughter, son in law and grandson had camped in the campground nearest the latest grizzly kill ( August 7 or 8th) in Yellowstone the week before the attack. They saw three grizzly the four days they were there. It's important to take the precautions and follow the rules. Kelly, my oldest daughter reports a pop up enterprise in Yellowstone is a bear spray rental enterprise. You deposit $25 and get a can of spray, when you bring the spray back you get $20 back. She had my midsize with her so did not "invest". They were tent camping.