Hi Brian,Nice tris! They're pretty! Look like sinaloae/nelsoni only with a black snout..
It looks nothing like the photo in Markell's "Kingsnakes and Milk Snakes" but Markells photo also looks nothing like the drawing in Williams and also doesn't resemble the photo on the web
I searched the internet for photos of this subspecies as Williams has no actual photo in his systematics book.(only a sketch)
There are several websites, but the odd thing is they all reference the same single photo, by Martin Schmidt. His snake looks like yours only with much more black tipping which presumably comes in with age like most triangulum...
Differentiating some Mexican and central American triangulum, is certainly a challenge to say the least. It's no wonder there's always such debate about validity of some subspecies.
Here's a couple sites of interest. One site links to web photos of all the subspecies with 3 pics of conanti, all 3 pics are the same photo
http://www.ritchiereptiles.homestead...ilkSnakes.html
http://www.pitt.edu/~mcs2/herp/Lampropeltis.html