Complex sentence: Prior to moving to this location in the late 1970s the high school was located on the west side of town in what is now known as Thompson Middle School located at the corners of Seventh and Main Street in Saint Charles.
Split into simpler sentences: Prior to moving to this location in the late 1970s the high school was located on the west side of town at the corner of Main Street and Seventh Street. This building now is used as Thompson Middle School located at the corners of Seventh and Main Street in Saint Charles.