Hi again,
I just took a look at the CA Dept of Fish & Game's online regulations book. Section 5.60 on pages 17 & 18 talk about collecting reptiles. If you have a fishing license, you're able to collect two California red-sideds. Here are the relevant quotes from the fishing regs:

5.60. Reptiles.
(a) General Provisions: Only the following reptiles may be taken under the authority of a sportfishing license, subject to the restrictions
in this section. The limit for each of the species listed below is two, unless otherwise provided. Limit, as used in this section, means daily bag and possession limit. No reptiles shall be taken from ecological reserves designated by the commission in Section 630 or from state parks, or national parks or monuments.
Common garter snake (Thamnophis sirtalis), except San Francisco garter snake (Thamnophis sirtalis tetrataenia): Special Closure: No common garter snakes shall be taken in Los Angeles, Orange, Riverside, San Diego, and Ventura counties.

Therefore, the daily bag limit on T.s. infernalis is two. What sweet news. I've sent them an e-mail to see if you could be reimbursed for real expenses. Very exciting. Talk to you soon,
Rick