I don't believe the crisis has as much to do with snake population as it does with destruction of habitat.
Some of the herpers I know who lurk around Humboldt county get some great photos.
The core of the problem is they are a locality specific snake, and the locality they once called home is dwindling fast.
If you see tetrataenia in the wild, PLEASE take photos, I know of a couple Thamnophis sites that would love to display them for you.
I have a ton of captive photos from Europe on display, always welcome and appreciate "in the wild" photos.