Complex sentence: The Smith Rock Shelter is a natual limestone overhang in McKinney Falls State Park near Austin, Texas believed to have been used as a shelter by Native Americans from 500 BCE until the 1700s.
Split into simpler sentences: The Smith Rock Shelter is a natual limestone overhang in McKinney Falls State Park near Austin, Texas. The shelter is believed to have been used as a shelter by Native Americans from 500 BCE until the 1700s.