Ralston and Vita Shannon, both 38, were each booked Sunday on charges of assault and "wrongs to minors."
Police documents allege Shannon struck Ralston twice in the back of the head with her fists and that he shoved her as she was leaving her apartment.
The wrongs-to-minors charge is used when children are present during an incident but not necessarily hurt. Police documents say the couple's 8-week-old child was present at the time of the altercation but apparently suffered no harm.
The documents say they were arguing over another child of Ralston's.
"We're saddened that this would happen, evolve this way," says Ralston's father, Larry Ralston. "We're hopeful that things will work out."
Aron Ralston and Shannon face fines of up to $999 and a sentence of up to a year in jail if convicted. It is standard procedure for suspects in domestic violence cases to be jailed, said Assistant City Attorney Vince DiCroce.
An attorney for Ralston declined to comment. It wasn't immediately clear if Shannon had an attorney yet.
Ralston was hiking in 2003 when he became trapped by a boulder and cut off his own arm to free himself. He went on to detail his struggles in a book and was later portrayed by James Franco in the film, 127 Hours.