sentences:  Its county seat is Oregon, and its largest city is Rochelle.Ogle County comprises Rochelle, IL Micropolitan Statistical Area, which is also included in the Rockford-Freeport-Rochelle, IL Combined Statistical Area.Ogle County was formed in 1836 out of Jo Daviess and LaSalle counties, and named in honor of Captain Joseph Ogle, a veteran of the Revolutionary War who settled in Illinois in 1785.