Complex sentence: Sam Rayburn was a member of the Chickasha High School football team that was the 1997 & 1998 Oklahoma State runner up, losing both times to Oklahoma, City Carl Albert High school.
Split into simpler sentences: Sam Rayburn was a member of the Chickasha High School football team, which was the 1997 & 1998 Oklahoma State runner up. Chickasha lost both times to Oklahoma City Carl Albert High school.