 Pre-historic campsites are found throughout the county along streams or other water sources; most are "open occupation" sites, though caves and rockshelters are often found along various rivers and streams.When Europeans first arrived in the area, the Tonkawa tribe was the most prevalent, though the Comanches and Lipan Apaches were known to travel through the area as well.Spanish explorers, including the Espinosa-Olivares-Aguirre expedition, traveled through the area for centuries though few permanent settlements were created for some time.