I tend to agree that YMSP would be a very good place for it. I've reached out to the Forest Service and suggested YSMP as one of the possibilities. We'll see what they say.
Here's the start of some detailed images of the stack. We'll start at the base:
Notice how the base is oval. At first I thought this was an artifact of an accident, but as I looked at it, I realized it actually was oval. I don't think anyone has ever noticed this before, but if you look at the previous photo of Betsy, once you know the base is oval you can discern that in the photo as well. It actually makes some sense that the base is oval since Betsy was built by a donkey engine/ farm equipment manufacturer (unknown who), and many steam tractors and stationary boilers had oval stacks.
Here's some measurements of the stack's base:
Nearly 15 inches in the short direction.
About 17.25 inches in the long direction (the broken flange requires a little extrapolation).
More later...