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Located within the Caribou-Targhee National Forest, Big Springs is the only first-magnitude spring in the country that issues forth from rhyolitic lava flows. It is the source of the South Fork of the Henrys Fork River.
Location: Fremont County, ID
Year designated: 1980
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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.
Last Updated: June 28, 2012