Tent camping in/around Yellowstone, without generators

Thank you all for your suggestions! I really appreciate your input. We've camped around bears before and have never been bothered. DD wants to go to Yellowstone, and it will be a quicker and more economical trip with the Prius and the tent than trying to drag the trailer up there. We do have bear spray, but I think that if you use the bear boxes and don't have anything smelly in your tent or car, that you won't have a problem.