I believe the Black Yetis are Camponotus nearcticus.
1. From looking at the pictures, there are differences between the queens.
a. The Black Yetis' queen has an elongated gaster (which C. nearcticus are known to have)
b. The Saxon's queen looks more bulky and more strongly built.
2. The workers of the Black Yetis eclosed as pale workers, which C. nearcticus are more prone to doing. The C. pennsylvanicus I've kept always eclose fully black and hardened.
3. The Black Yetis seem to be growing at a much slower pace (Why shouldn't they? Their colonies only get to about 100 workers of so).