SILVERTON, Colo. (AP) - Colorado officials expect the head of the Environmental Protection Agency to join them on a tour of an old gold mine where the EPA inadvertently triggered a spill of 3 million gallons of tainted wastewater.

The tour is Friday at the Gold King Mine in southwestern Colorado.

Jacque Montgomery, a spokeswoman for Gov. John Hickenlooper, said state officials expect EPA Administrator Scott Pruitt to be present. The EPA refused to say whether Pruitt would attend.

Pruitt was in the Denver area Thursday.

Hickenlooper, U.S. Sens. Michael Bennett and Cory Gardner and U.S. Rep. Scott Tipton are scheduled to be at the mine.

The EPA designated the Gold King and 47 other sites in the area a Superfund district last year.

The August 2015 release at the Gold King tainted rivers in Colorado, New Mexico and Utah.