Sounds like an interesting family you're researching. I guess it's mysteries like yours that keep us going!
In 1915 my great-uncle, Arthur C. Vonado, obtained a homestead patent in Fergus Co. MT. He married and had children there before moving his family to Oregon. In 1916 a Charles H. Vonada received a Homestead Entry-Stock Raising land patent in Powder River Co., Montana. During World War II Helena newspapers mentioned an active member of the Navy Mothers Club; 17 times she was Mrs. Charles Vanada and 2 times Mrs. Charles Vonado. I haven't figured out where Charles Vonada fits in but do know he was born in Kansas, where many of the family gathered before heading farther west.