The first Americans (that is, white citizens of the United States of America, as opposed to Native Americans) to visit present-day Orange County were otter hunters. According to historian Leo Friis, "Sea otters were once plentiful along the pacific coast and dwelt in great numbers in the kelp beds off Dana Point. The pelts of these animals were very valuable and efforts by American, English, and Russian sea captains to trade for them met with determined opposition from Spanish government officials who forbade all trafficking with foreigners,"
This didn't stop these greedy Yankees, though. They wanted otter pelts and were determined to get them, even if it meant lying, stealing, and cheating. In the 1800s, Yankee captains like John Brown and George W. Eayrs sailed their pirate, er, merchant ships with guns along the coast, decimating the otter population.
Another big "draw" for early Yankees was beavers, whose pelts were also valuable commodities. The famous pirate, er, pioneer Jedediah S. Smith was one of these beaver hunters. He was given permission too pass through California and leave, but Smith was so obsessed with trapping beaver that he over-stayed his welcome, much to the chagrin of Governor Echeandia.
Another yankee pirate, er, hunter, I mean, merchant was William Wolfskill (which is actually a pretty badass name). He passed through present-day Orange County to profit from killing native animals. Wolfskill was apparently quite the diplomat. He gained favor with the local Spanish padres by slaughtering Indians who would not cooperate with the Mission system. He was therefore allowed to stay and hunt.
The famous beaver hunter. His hat is made from a dead beaver.
