Cloe looks a lot like my late Esther. She was listed by the shelter as a Plott hound, but I could easily believe lab/rott mix. There was also a guy in our area (east central Wisconsin) who was crossing Rottweilers and Plott hounds - trying to make a better bear-hunting dog (because the Plotts bred since the18th century were not good-enough.)
If you look for images of Plotts, there are some that look very much like Cloe. Plotts have a howl that sounds like a portal has been opened, letting all the hellhounds out. You would probably notice that.
Here's a link to Esther's photos on this forum: Esther