Actually you are all wrong
its not Thamnophis marcianus (the Cheequred Garter) which ranges in Texas and neighbouring states, parts of arizona and SE Ca, and adjacent parts of mexico......
It is in fact Thamnophis elegans (the TERRESTRIAL Garter snake
which can be found in most of the west half of the USA excluding deserts and adjacent parts of SW Canada, so there
the eastern garter is not found in SW usa and looks nothing like the one in the pic (although T.e does have widley varying makings)
please dont disagree, i have proof and I wont be very happy