If someone told you there was a way to travel from Portlad to Seattle for $9.00 would you believe it? Well its true if you dont mind trasfering to 4 or 5 different buses along the way. Its a lot cheaper than going o Greyhound at $30.00 each way and Amtrak costing more. Years ago the hippy bus compay Green Tortois use to run routes between Portland to Seattle for $15 each way but stopped it eight years ago. So if you are a cheapskate like I am then this is the way to go. Below is how I did it.

Downtown Portland : $3.00/ C-Tran #105 Express bus to Salmon Creek Park & Ride.
Salmon Creek P&R : $1.00/ CAP mini-bus to Longview, Washington (Free if you have a student I.D.)
Longview Transit Ct : $1.00/ CAP mini-bus to Tumwater, Washington (Free if you have a student I.D.)
Tumwater Square st : $1.50/ Intercity Bus #13 to downtown Olympia bus transit center
Olympia Tansit CT : $1.00 (with all day transfer from bus #13)Intercity Bus #603 to dowtown Tacoma
Tacoma downtown Commerce St. : $1.50/ Pierce Transit bus #594 to downtown Seattle.