Thank you very much for your help.
The four Sellman brothers came of age while living in Audubon County, and I believe they had strong ties to that area, especially with their grandparents living there. Their parents lived in Keya Paha County, Nebraska in 1890, and the grandmother left the grandfather, who left the county and moved around the state until he ended up in Iowa in 1892. I'm sure the boys felt that Audubon County was more of a home than Keya Paha County. Earlier this year, I was told that they might've gotten in trouble with the law and had to flee the county. I'll have to do more digging to see if that's true.
I appreciate the time you took to help me.
Kir