I don't know enouph about Mitten Ridge except that most of it's points are nasty climbs. If I did alot of hiking in that area I would have added it. Being in Colorado I don't have the chance anymore to check that area out.
I think I've been down Casner Canyon, it thats the one that starts at the fish hatchery. I did it about 15 years ago so I don't remember it much. We hiked up Schnebly hill road and down Casner Canyon.