Complex sentence: The Escondido Sub in North County of San Diego, is a 22-mile branch line between Oceanside and Escondido, California, primarily used today by the Sprinter light rail and local freight trains serving Escondido industries.
Split into simpler sentences: The Escondido Sub in North County region of San Diego County, is a 22-mile branch line between Oceanside, California and Escondido, California. It is primarily used today by the Sprinter light rail and local freight trains serving Escondido industries.