Welcome Popeye! I hope the recent spinach problems haven't been keeping you down. LOL. All kidding aside. If you live in Oregon the snake you saw was a northwestern garter snake. Here is a link to a good resource on northwestern herps.
northwest herps
Oregon is a beutifull place with a lot of gartersnake diversity. As you can see from the link above, northwestern garters are very variable in color and number of stripes. They would make a fun breeding project as its not currently known if all of color variations are genetic or not. Northwestern garters are very abundant there, so if you focus on wetland areas you shouldn't have trouble locating some of them. Depending on where you live you also have Oregon Red spotted garters and Valley garters. Good luck on your hunt. Northwestern gartesr are often thought of as slug specialists, but they will eat worms, fish, amphibians, and scented mice as well.