From what i've heard over the few trips i've been through over the pass, and onto "the other side" (Eastern Washington) where sagebrush and dirt dominate the landscape, all the Tiger Mountain stations make it easily over the mountains. KZFM from Lewiston, ID has the most fights in the area of Easton and Ellensburg, with KBKS 106.1 from Seattle. KZOK and KMPS have the most dominate signal on 102.5 and 94.1 respectively, over on the other side of the mountains.
Meanwhile on this side of the mountains, the clear winner is KPQ-FM 102.1 in Wenatchee, with 107.3 KFFM in Yakima sometimes making it past the mountains. With KPQ's transmitter site on top of Mission Ridge, their signal makes it to plenty of locations on the western side of the state and including Snoqualmie Pass, but never Seattle in general. It's like the mountains immediately behind Seattle have a shadow effect, because in West Bremerton, Brinnon, Quilcene, and Sequim, KPQ-FM most times comes in like a local station, while KSWW in Aberdeen takes over control of the frequency in places like Seattle, East Bremerton, Silverdale, Purdy, and Belfair, but yet, KFFM in Yakima and CHBE in Victoria, both on 107.3, have fights with each other in the Silverdale and Poulsbo areas. I have heard of reports of Wenatchee and Spokane stations making it across the mountains as well, in Mount Vernon and places in Island County, but I never really travel to those areas to confirm that, other than hearing things from 3rd parties.
LOL...I guess you can say, the Easton/Ellensburg area is the "battleground" for signals on the eastern side of the state, and Kitsap County and Jefferson County, are the "battleground" for signals on the western side of the state.
One other station on the western side of the mountains, KCMS 105.3, has a couple translators on this side in Aberdeen and in the way southern Puget Sound area. I wouldn't be suprised if they eventually powered up a translator in Easton or Ellensburg in the near future. Religious stations tend to do that kind of thing.
As far as I know though, all the translator stations on Snoqualmie Pass, we're pretty much snuffed out, when more stations powered up or moved to other sites or frequencies both on the western side and eastern side of the pass.
And it seems, even if you have 5,000 or 6,000 foot tall mountains standing between each half of a state, radio (or even TV) signals can somehow conquer those conditions. Just imagine though, if the Cascades weren't there. Besides completely different weather, we'd have different radio/TV signal conditions as well across the state.