Your area is crawling with snakes of all varieties, provided you know where and WHEN to look. The "when" is perhaps more relevant right now because by this time of year you're not likely to find much except on the roads very late at night, which might be a problem with your parents. My son, age 13, gets a a kick out of staying up late and driving in the hills, but then again his dad (me, of course) comes up with the idea in the first place.
A lot of beginners make the mistake of thinking that snakes are out and about during sunlight hours. This is partially true for species like racers and garter snakes, but in general they prefer to remain concealed. Snakes are after all a valuable food source for birds, who have great eyesight. Plus, snakes require (more or less) constant humidity in order to be comfortable. If a board is bone dry underneath, you're not as likely to find something than if it is moist. This is why you find animals under boards and such in the springtime. I know of a single piece of plywood that gave up two species of garter snake, a couple of gopher snakes, a racer, a rattlesnake, a dozen ringnecks, and one mountain king-- just this year alone. On the other hand, I've seen nothing under it for the last three months.
All is not lost though. After the first rains of the season you will start finding this year's babies. Find a sunny place near a wooded area where there is debris scattered around, such as boards, sheets of metal etc. Go there late in the afternoon on a warm day after a recent rain and look underneath them. You WILL eventually find something. These are the same places you will find adult animals in the springtime.
As for mountain kings, you have to either be incredibly lucky or a lot more experienced to find one as easily as you would a garter, ringneck or common king. They inhabit a very specific micro-habitat, which you must be able to identify before you will find them.
By far, the best indicator for snakes is the presence of lizards. If there are a lot of lizards around, there ARE snakes to eat them. All you have to do is work out the details.
Hope this helps.