Hidden Valley was a good clue. CNL bought 440 acres in Hidden Valley from Plum Creek on May 9, 2008, for $650,000. Could this be what you've heard about?
From poking around on the map, it looks like Burlington Northern sold all their property in the area to Booth Creek, WA Dept of Recreation, and Plum Creek back in 1989. Or perhaps I missed a parcel somewhere.
(By the way, in the panel on the left, you can click on Assessor's records to get lots of info. You can also click on Layers/Aerial Photos/DOQ-2000, then hit Refresh, to see the property boundaries superimposed on an aerial photo.)