i think this is 230kV. It comes from the White River generating station near my home in Sumner and goes somewhere east of the mountains. I think it's some sort of backup / load balancing line owned by Puget Sound Energy. It's energized and I think it's bringing power from the east to west because the White River plant is no longer operating so i think this helps take it's place. Maybe in the event of a massive power grid failure on BPA's system the white river plant could be put into operation and this line could take power east across the mountains. my theory anyways. ***update*** I've figured out that this most likely is an interconnect with the Rock Island dam, 12 miles south of Wenatchee on the Columbia river. A pole near the white river end has the mile tag of 125, which leads me to beleive that it's fed from the east end since that's mile zero.