I just found this forum and thought I would contribute a few pics of wild Thamnophis.

Some Puget Sound Garters (Thamnophis sirtalis pickeringii)






A colorful Valley Garter from Central Washington (Thamnophis sirtalis fitchi)


An exceptionally bright Red Spotted Garter (Thamnophis sirtalis concinnus).


A California Red-sided Gaters (Thamnophis sirtalis infernalis).