Question posed about Butte Miners' Union benefits

I'm writing this for my 74 year old dad. My father was a miner most of his adult life. He worked underground in Butte 1965 to 1975. He remembers paying into the Union, Miners Union #1. He believes he paid some into a pension type plan. Can you or anyone in Butte help him find out if there is any money or other benefits from way back then?

— Nick Hoban, 303 East Don Drive, Pueblo West, Colo. 81007;; (born in Butte 😉)