U.S. Geological Exploration of the Fortieth Parallel
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UNEXPLORED
The U.S. Geological Exploration of the Fortieth Parallel was a major 19th-century American scientific survey that mapped and studied the geology and natural resources along the 40th parallel in the western United States.
Referenced by (1)
| Subject (surface form when different) | Predicate |
|---|---|
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Grove Karl Gilbert
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employer |