Doh!
Shoulda looked more closely.
We have those around here, and they're pretty quick to defend themselves against anyone stupid enough to get in their chili.
I'm different from most folks I know by leaving all snakes alone, including the very few venomous (mostly the only very low-level venomous Copperhead) ones in my area.
I would only kill a venomous snake if it got into my humble abode somehow, but I'd catch and release a non-venomous one.