My theory that a disaster struck the family panned out. Young Harvey Hulen was living with an aunt in 1855, and later spoke about living in his stepfathers house in 1862.
Any clues how William Hulen died? Boone County had a massive movement of men to California in 1850, and I found William included on an extensive listing of those who went. I'm wondering if he died there, or on the trek home.