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About National Natural Landmarks
A National Natural Landmarks (NNL) is a natural area that contains an outstanding example of the nation's natural history—either biological, geological, or both. It is officially designated by the Secretary of the Interior.
To be nationally significant, a site must be one of the best examples of a type of biological community or geological feature in its natural region. Experts evaluate sites based on how well they represent a natural feature (illustrative value) and how well the site is preserved (condition of the resource.
Sites may include:
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Biological ecosystems (forests, wetlands, lakes, etc.)
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Geological formation and landforms
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Fossil beds or evidence of past life
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Place that show active natural processes
These features are grouped by natural history themes and subthemes. For example, the “Lakes, Ponds, and Wetlands” theme includes subthemes like crater lakes, swamps, marshes, bogs, and springs.
Some NNLs are the last or best examples of their kind in the country or even the world. They help protect rare places and support research, education, and conservation.
As of December 2024, there are 606 NNLs that have been designated within the United States and Territories.
Visit the NNL Directory to view a map and list by state.
They vary in size from less than four acres to over 900,000 acres.
Some NNLs protect a single feature (like fossil beds or rock formations). Other NNLs encompass very large, diverse landscapes with many types of natural features.
Yes! Some well-known NNLs include:
- the volcanic crater Diamond Head on the Island of Oahu, Hawaii,
- Okefenokee Swamp in Georgia, and
- Rancho La Brea tar pits in Los Angeles, California.
Some NNLs are open to the public. Others, especially on private land, may not be. Public access is not required, and landowners decide if visitors are allowed. Always check before you go to see if a site is open to the public and adhere to all landowner rules.
NNLs are protected through the conservation efforts of its landowners. The National Park Service may help with conservation at the request of the landowners.
National Natural Landmark Designation
Sites considered for NNL designation include:
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Terrestrial and aquatic ecosystems
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Geological landforms and formations
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Fossil evidence of evolution or ancient environments
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Places that show active natural processes
Each site must be one of the best examples of its kind in its region, based on condition, rarity, and illustrative value.
The site must be one of the "best" examples of a type of biological community or geological feature in its biophysiographic province. "Best" is gauged primarily on illustrative value and condition of the resource
Here’s a simplified look at the process:
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Search and Identify: Experts review a natural region to find the best examples of biological or geological features.
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Notify Landowners: When a promising site is found, landowners are informed and must give permission before any evaluation can happen.
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Scientific Evaluation: Qualified scientists carefully study the site’s features and write a detailed report.
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Peer Review: Three additional scientists review the report to make sure it’s accurate and scientifically sound.
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Public Input: If the site meets national significance criteria, the public and landowners are invited to comment on the proposed designation.
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Review and Recommendation: The National Park System Advisory Board reviews everything and makes a recommendation to the Secretary of the Interior.
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Designation: The Secretary reviews all materials and recommendations and may officially designate the site as a National Natural Landmark.
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Notification: Landowners, elected officials and the public are informed.
No. NNLs can be found on:
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Federal, state, county, municipal, or tribal land
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Private land owned by individuals, nonprofits, universities, land trusts, or businesses
About 52% of NNLs are on public land, 30% are fully private, and 18% are mixed.
No. The land stays under the same ownership.
Yes, unless:
- The site's nature features are lost or destroyed
- There were serious errors in the evaluation or designation process.
No. The federal designation does not create any new restrictions. However, local or state governments may have their own rules that apply.
There's no clear answer. The impact on value depends on the individual property and how the NNL designation is viewed locally.
No. There is no formal written agreement between NNL landowners and the National Park Service. The landowner's permission for NNL evaluation is considered an agreement to participate in the program.
Landowners may:
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Get assistance with conservation planning, grants, environmental review and technical support
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Receive letters of support from the National Park Service to protect their site
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Be recognized for protecting a nationally important natural resource
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Receive a certificate and a plaque and have access to NPS educational materials
Yes. If a site loses the natural features that made it significant, it may be removed from the National Registry of Natural Landmarks and the NNL plaque returned.
No. NNLs and national parks have different criteria and processes. Only 26 of the 606 NNLs are located within 21 different units of the National Park System.
Not always. Plaques are expensive and usually placed in a shared location. However, certificates can be given to multiple landowners.
Not always. NNL boundaries are drawn to include only the nationally significant natural features. Sometimes they may include an entire park or refuge but more often are smaller areas with the park or refuge.
National Natural Landmark Program
The NNL Program was established in 1962 using authority from the Historic Sites Act of 1935. The first NNLs were designated in 1964.
The NNL Program is managed by the National Park Service, which is part of the Department of the Interior.
The NNL Program aims to:
- Help preserve the best examples of U.S. natural features
- Support science and education
- Increase public appreciation of natural history
- Encourage conservation of the nation's natural history
Yes. The program follows regulations listed in 36 C.F.R. Part 62, last updated in 1999. These rules guide how the program is managed by the National Park Service, but they do not control land use or ownership.
The NNL Program:
- Is national in scope,
- Includes all types of land ownership
- Focuses on the best examples of natural resources, and
- Treats geologic and biological features equally.
Managing National Natural Landmarks
Generally, yes. But the program encourages landowners to protect the natural integrity of their site. Destructive development would go against the purpose of designation.
Not directly. But National Park Service staff can help landowners apply for grants or write letters of support.
Yes. NNL program regulations require the National Park Service to monitor the condition the features that qualified them for NNL designation. Site visit reports descrive the condition, any damages or threats, and possible actions to help protect the site.
No. While they share a common goal of preserving the natural and unimpaired condition of NNLs and national parks, management policies for national parks do not extend to NNLs. Individual management of NNLs varies depending upon ownership.
No. The National Historic Landmarks Program and the National Register of Historic Places are for cultural history sites, not natural ones, and follow different laws and processes.
Last updated: December 3, 2025