Wyoming's Congressional delegation says the state could receive over $500 million in abandoned mine land payments thanks to a provision in the massive federal highway spending bill. 

Money to clean up old, abandoned coal mines comes from current mining operations. Companies pay a fee on each ton of coal they mine which goes into the abandoned mine land fund. About half of AML money comes from Wyoming mining operations but because of a cap, the state only get a fraction of that back.  

At the tail end of the 1300 page highway bill is a provision which requires the federal government to lift that cap and pay states back for money collected under it. For Wyoming, that amounts to about $250 million dollars. Without the cap, Senator Barrasso, Senator Enzi, and Representative Lummis project that AML money would amount to around $350 million more going forward.

The cap was a source of contention for Wyoming politicians who argued that the federal government was unfairly keeping the state’s money.

“It came down to a matter of fairness to return what was wrongfully taken from Wyoming years ago," Senator Barrasso said in a statement.

But this provision isn't law yet. After the US Senate votes on the measure it goes to President Obama for his consideration.