cycling from Seattle to Weiser, Idaho (route help!)

[CotyH]

Hi All ~  I'm planning on cycling from Seattle to Weiser, Idaho this June and wondering if anyone might be able to help me/ give tips on the best route to get there.  I've done a basic google maps search and it has me riding a bit on I-90 (around snoqualmie....) would love to avoid that if possible!  Also, does anyone have experience with the Iron Horse trail?  I've got 32 cc Schwalbe Marathon tires on my bike which worked great last summer for biking the Transamerica, but I don't know how they would do on that trail.

Thanks!

[beloh21]

I rode most of the Iron Horse a few years ago and you should be fine on 32's west of the Columbia.  The stretch that runs through the Yakima Firing Range can get soft and sandy (and muddy if it's been wet) but you'll probably want to head south before that, maybe take route 821 from Ellensburg to Yakima? The Iron Horse east of the Columbia is another story; sand, big rocks, and goat heads.

[johnsondasw]

Don't try Snoqualmie Pass on the freeway. It's undergoing years of construction, as in forever. The John Wayne Trail is good there, though. 821 the "River Road" from Ellensburg to Yakima is not to be missed!  It is one of the best biking experiences you can have and should follow Old HWY 10 from Cle Elum to Ellensburg.  They are both through awesome desert canyons.  After Yakima, there are nice secondary highways, albeit some have fast cars so watch your mirror. From Cle Elum east, this country can be hot in June.   

[CotyH]

Thanks so much both of you for the tips!  This helps a whole lot.  :-)