In my opinion...Damn little good if any.
If you were to have a protected habitat where you kept people out, then the snakes would reach normal healthy populations based upon the land's ability to support them.
Unfortunately, the opposite is true with E. Indigos, Pines and san Francisco Garters. With each of these animals, their enviroment is being swallowed by human encroachment. Without habitat to live on everything else is irrelevent.
All we are doing is making sure these species pass into extinction without the option of captive breeding (which is not a cure-all but at least provides a small hope).
Also..limiting or prohibiting possession does not stop the ignorant from killing them on sight.
Frank
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"The luxury of not getting involved departed with the last lifeboat Skipper..."