SIOUX CITY — A western Iowa man accused of raping a teenage baby sitter has been sentenced to two years in prison. Colby Mauch, 25, of Castana, was sentenced Thursday. He had pleaded guilty to one count of assault with the intent to commit sexual abuse. Police say Mauch traveled to the then-17-year-old girl’s home, where she was babysitting six children. While the children were outside, Mauch raped her.