Packing for a week in Yellowstone National Park with kids sounds like the kind of thing that requires three giant suitcases, a roof box, and a mild emotional breakdown. But after multiple national park trips with our family of four, we’ve learned something important: You do not need that much stuff. A week's worth of clothing in a carry-on for a Yellowstone National Park trip. In fact, you can absolutely pack for a 7-day Yellowstone trip using: one carry-on per person one per