Sorry to report I don't think our Williams are the same ones. Mine is William Wilbur Heth who married Mary Ellen Frederick. They had only one son, Thomas Frederick Heth. He married Lovina Dingman. Thomas and Lovina had several children in Illinois, then moved to the Los Angeles area where their daughter, Hazel Ellen Heth, married Chester Alfred Savage. These last two are my grandparents. As far as I know none of them were ever in Montana. They all died in California or Nevada.
Sorry this didn't work out - hope you find the right line soon.