Revise coal severance tax coal washing credit

This bill extends the expiration date of Montana's coal severance tax credit for coal washing from July 1, 2017, to July 1, 2027. The credit allows coal mining companies to reduce their severance tax liability when washing coal to remove impurities before sale. The bill amends two existing laws (2009 and 2015) to update the termination date and requires the secretary of state to notify Montana's tribal governments. The change takes immediate effect upon enactment, providing continued tax relief for coal producers using washing processes.