Happy New Year Mr Redwood! Good to bring up the Skagit tread again, yes!
I searched for Skagit yarders at Craigslist and found a BU98 with a 110 ft tower, may you have mistaken that for a BU99? I know only of the Wayne Stone BU99 in logging operation today (the one picked up in California), then it is 1 at McPauls in Centralia (think it was 2 some years ago), I think it's one dredging a little outside Centralia and it's some remains of 2 up on northern Vancouver Island, one is the same I filmed operating for MacMillan Bloedell in 1997. Just east of Chehalis it's 2 large Skagit yarders stored, I have heard rumors they are 199's, but they may as well be BU99's or 98's. I would think both 99's and 98's have been popular for draglining.
We should have had a production record from Skagit, but it has been hard to find, still I suspect Modern Machinery to have it, inherited from Pacific Manufacturing. Apropos machines stored away, did you hear about the Arcata Madill 044 suddenly showing up in Chehalis last year?
Torkel