'Wolf-like' creature shot on Montana ranch puzzles experts
bbc.com
bbc.com
Consider brown bears and polar bears. We consider them 2 species yet they can successfully interbreed. The main reason they don't is that their ranges haven't historically overlapped. Geography, not biology, was the separator. You could view them as one species with a bivariate distribution, in the late stages of diverging into two.
Canids likewise viewed as one species with significant ecological clustering, but divided this time by behavior.
I would say this was a house pet in the very recent past (whether a dog, or some wolf-dog type animal).
Perhaps some gente moved to Montana and took their pet Chupacabra with them.
Could be an extinct Hemicyoninae, meaning “dog-bear”.