These snakes are often found in my yard:
Sharp Tailed snake (small and harmless. I have them everywhere)
Gopher snake (has a bad temper if bothered, but otherwise harmless. They will also shake their tail to act like a rattler)
Rattlesnake (get them regularly, killed 4 last year)
and
Pacific Ring Neck snake (a few, but haven't seen one in a few years)
Kingsnake (I used to see them regularly, but sad to say I haven't seen one in years)