Bitter Lake Group
Located within the Bitter Lake National Wildlife Refuge, the Bitter Lake Group contains more than 30 natural sinkhole depressions formed by solution of gypsum-bearing rocks. The highly saline artesian lakes provide habitat for the only inland occurrence of a marine alga and two rare fish species. The site offers one of the best examples of undisturbed shrub-grassland and the process of succession and restoration to natural conditions following a disturbance.
Year designated: 1980
Please remember, National Natural Landmarks (NNLs) are not national parks. NNLs are owned by a variety of public and private entities and allowing visitation is at their discretion. Many NNL sites maintain public websites where additional information may be found.