1920 Federal census,Maxwell,Pontatoc County,Oklahoma
Robert H Bull, head, m, w, 28 married, Tx, Wis, Ok
Mariam, wife, f, w, married, 20, Ok, US, Ok
Mamie, daughter ,f, w, 2
It is interesting that Robert Bull said his mother, Sarah Ann Brown, was born in Oklahoma. She was born in Arkansas, but they were living in what is now Leflore Co, Ok (then it was Choctaw Nation) just before they moved to Denton Co., Tx -- maybe that is what he was thinking of?