"Powder River, let 'er buck" was a common phrase among cowboys. I don't know if anyone has released a whole collection of Powder River Jack & Kitty Lee, they were great singers. Jack had the habit of claiming authorship of other peoples songs, which did not endear him to the rest of the cowboy singers. But his song "Powder River"(which he did write) is a great piece of work. The only other song I think that I've heard them sing was "Tying Knots in the Devils' Tail", which, of course he claimed copyright for.

Mark Ross