Although recorded history of the tribes in this region does not begin until the explorers and missionaries arrived, there is evidence of many tribal settlements in the area later known as Cambria. It is estimated that as many as 30,000 people inhabited the area in the time (some 1,000 years) before the Spanish arrived. Experts believe these tribes to have been migratory and used Cambria as a seasonal settlement; other scientists are convinced that they lived there permanently. Most agree that they fed themselves with shellfish and seafood, as well as obtaining food from travels inland to hunt and gather seeds. A variety of artistically-crafted implements have been discovered, including spears points and arrowheads made from obsidian; basalt, sandstone, and granite were used to make mortars and pestles; soapstone kettles and stone hammers were also found. These early inhabitants were skilled basket and net makers and fashioned jewelry from crab claws, abalone shells, and the teeth of sharks and whales. The presence of soapstone (steatite) provides evidence that they traded with the Catalina Island tribes, whereas the lack of metals and glass indicates that they did not trade with Europeans or Asians.