Gianforte spokesman Travis Hall said the Republican has been working with other lawmakers to make sure the bill introduced Thursday can pass. Hall would not give further details.
The measure would remove public lands north of the park from future mining claims. An identical bill sponsored by U.S. Sen. Jon Tester, a Democrat, had stalled.
Two companies are seeking to develop gold mines north of Yellowstone.
Local residents and businesses say the projects could pollute waterways and discourage tourism.
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