My great grandfather was also Marion Sylvester Arbogast. He was married to Lilian May Arbogast. I know my grandfater, Elmer Russell Arbogast was born in Montana, probably somewhere late 1890's or early 1900's. He was a gold miner and married my grandmother around 1920. They had my mother in 1921. They divorced (he was a terrible rounder) and he then married Isabella Watson who bore him three children.
I haven't been able to find any additional information. If you have any new information I would appreciate your passing it on to me.