Complex sentence: For most of its history, it has been the only high school in Keams Canyon; the public Cedar Unified School District opened White Cone High School in 2005 and closed it in 2012.
Split into simpler sentences: For most of its history, it has been the only high school in Keams Canyon. The public Cedar Unified School District opened White Cone High School in 2005 and closed it in 2012.