[andyoconnor83]

Just to clarify with the example given, they wouldn't be hybrids, but unnaturally occurring intergrades, since they are technically the same species, but different sub species ie. Both are Thamnophis sirtalis, but the P.S. are T. s. pickeringii and the eastern are T. s. sirtalis. In any case, as was mentioned here, they wouldn't be very attractive most likely, unless they were easterns considered Florida blues... then you could get some very nice looking snakes, but for all reasoning, I would keep them separate. The babies would be fertile as well, just like if a Pugent sound (T. s. pickeringii) and a valley (T. s. fitchii) garter bred, which happens naturally in a few locations here in Washington state.