1. Yellowstone National Park (Wyoming, Montana, Idaho)
2. Grand Canyon National Park (Arizona)
3. Yosemite National Park (California)
4. Rocky Mountain National Park (Colorado)
5. Great Smoky Mountains National Park (North Carolina, Tennessee)
6. Zion National Park (Utah)
7. Acadia National Park (Maine)
8. Grand Teton National Park (Wyoming)
9. Olympic National Park (Washington)
10. Glacier National Park (Montana)