| Alabama | Alaska | Arizona | Arkansas | California |
| Colorado | Connecticut | Delaware | Dist. of Col. | Florida |
| Georgia | Hawaii | Idaho | Illinois | Indiana |
| Iowa | Kansas | Kentucky | Louisiana | Maine |
| Maryland | Massachusetts | Michigan | Minnesota | Mississippi |
| Missouri | Montana | Nebraska | Nevada | New Hampshire |
| New Jersey | New Mexico | New York | North Carolina | North Dakota |
| Ohio | Oklahoma | Oregon | Pennsylvania | Rhode Island |
| South Carolina | South Dakota | Tennessee | Texas | Utah |
| Vermont | Virginia | Washington | West Virginia | Wisconsin |
| Wyoming |
According to the National Park Service, National Historic Landmarks "recognize and encourage the conservation of sites that contain outstanding biological and geological resources. Sites are designated by the Secretary of the Interior for their condition, illustrative character, rarity, diversity, and value to science and education."
Select a State to see what National Natural Landmarks I've visited.
See my statistics page and tracking spreadsheet.