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Comprised of deep erosion canyons with rugged rims, Rainbow Basin is an outstanding example of geologic processes. The site contains significant fossil evidence of insects, larger Miocene mammals and mammal tracks.
Location: San Bernardino County, CA
Year designated: 1966
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Please remember, National Natural Landmarks (NNLs) are not national parks. NNL status does not indicate public ownership, and many sites are not open for visitation.