The Biden Administration will give Ohio $46.4 million this year to help address the state's thousands of abandoned mines.
Secretary of the Interior Deb Haaland was in Cincinnati Wednesday to announce the award and meet with state officials and union leaders.
"People spend years dealing with the serious environmental and health risks caused by sites like these, but I believe we have the resources to end this cycle," she said.
Runoff from mines can pollute local water sources. The sites can also pose physical dangers when they collapse or when people get trapped inside them.
Haaland and union leaders say the money would not only clean up many dangerous sites, it would also create good-paying union jobs.
State officials will decide which projects get the funding.
Ohio's Abandoned Mine Land Inventory System documented more than 4,300 abandoned underground mines a decade ago. But officials also say there are probably more, since many mines were started before modern mine reporting laws existed.
A map from the Ohio Department of Natural Resources show most of the known abandoned mines are concentrated in the eastern portion of Ohio.