Native species can be taken for non-commercial use with a fishing liscence. Rattlesnakes may be taken without anything. There is a list of snakes you can't take on the DFG website. Here is from the site:
A current California freshwater sportfishing fishing license is needed to collect non-protected reptiles and amphibians in California, except for rattlesnakes. (See the California Fish and Game Commission web site for exceptions, such as scientific collecting permits.) This license must be displayed by attaching it to the "outer clothing at or above the waistline so that it is plainly visible...."
Snakes that may NOT be taken:
Snakes
Baja California Ratsnake - Bogertophis rosaliae
Southern Rubber Boa - Charina umbratica
San Diego Mountain Kingsnake - Lampropeltis zonata pulchra
San Joaquin Coachwhip - Masticophis flagellum ruddocki
Alameda Whipsnake - Masticophis lateralis euryxanthus
Yellow- bellied Sea Snake - Pelamis Platurus
Two-striped Gartersnake - Thamnophis hammondii
Giant Gartersnake - Thamnophis gigas
San Francisco Gartersnake - Thamnophis sirtalis tetrataenia
Common Gartersnake - Thamnophis sirtalis (From Southern California, only)
Snakes and lizards that MAY be taken:
(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.
(b) No sportfishing license is required for the sport take of any rattlesnake.
(1) Painted turtle (Chrysemys picta): Limit: No limit.
(2) Slider Turtle (Pseudemys (Trachemys) scripta): Limit: No limit.
(3) Spiny softshell turtle (Trionyx spiniferus): Limit: No limit.
(4) Western banded gecko (Coleonyx variegatus)
(5) Desert iguana (Dipsosaurus dorsalis)
(6) Chuckwalla (Sauromalus obesus)
(7) Zebra-tailed lizard (Callisaurus draconoides)
(

Colorado Desert fringe-toed lizard (Uma notata)
(9) Mojave fringe-toed lizard (Uma scoparia)
(10) Desert spiny lizard (Sceloporus magister)
(11) Granite spiny lizard (Sceloporus orcutti)
(12) Western fence lizard (Sceloporus occidentalis): Limit: Species No. 12- 6 have a limit of twenty-five (25) in the aggregate
(13) Sagebrush lizard (Sceloporus graciosus): Limit: Species No. 12- 6 have a limit of twenty-five (25) in the aggregate
(14) Side-blotched lizard (Uta stansburiana):Limit: Species No. 12- 6 have a limit of twenty-five (25) in the aggregate
(15) Western skink (Eumeces skiltonianus): Limit: Species No. 12- 6 have a limit of twenty-five (25) in the aggregate
(16) Desert night lizard (Xantusia vigilis): Limit: Species No. 12- 6 have a limit of twenty-five (25) in the aggregate
(17) Long-tailed brush lizard (Urosaurus graciosus)
(1

Tree lizard (Urosaurus ornatus)
(19) Small-scaled lizard (Urosaurus microscutatus)
(20) Desert horned lizard (Phrynosoma platyrhinos)
(21) Short-horn