Yellowstone and Grand Teton National Parks-Las Vegas-Antelope Valley-Horseshoe Bend-Salt-Lake Tour Covering 15 Major Attractions (Options for 7 or 8 Days) (黄石和大提顿国家公园-拉斯维加斯-羚羊谷-马蹄湾-盐湖之旅，涵盖 15 个主要景点（7 天或 8 天可选）)