I see that you are located in Los Angeles so YES it is DEFINETELY a San Diego Gophersnake- Pituophis catenifer annectens
Check out the links below. This site is VERY handy to help identifying Snakes, Lizards,Turtles, Frogs, and salamanders. One if the full site and if you click on what you are looking for you will see pics of whatever species you want to look up. Then if you click on the Scientific Name it will bring you to another page with more pics of the sub species and info about it.
This link will help you see WHERE and WHAT subspecies are located in the map. And it also shows pics to compare.
http://www.californiaherps.com/snake...annectens.html
Here is the full site:
http://www.californiaherps.com/
Here is ALL of California's Snakes Species
http://www.californiaherps.com/snakes/snakespics.html
Hope this helps. I find it a GREAT resource when I am trying to ID something or which sub-species..