I have a question about getting from a northbound Cascades train to SeaTac. Should I get off at Tukwila or Seattle? Amtrak describes the connection from King Street Station to SeaTac by light rail in the timetable, but there is an airplane icon by the Tukwila station in the schedule. The train wastes quite a bit of time going the last few miles into Seattle in addition to the closer proximity to the airport of Tukwila. Is it easy to get from the Tukwila Amtrak station to the light rail station?
Between Tukwila station (served by Amtrak Cascades) and Tukwila International Boulevard station (served by Link light rail) you can catch the RapidRide F Line bus. RapidRide is King County's faux-BRT system (makes fewer stops, hits fewer red lights). The trip between the two stations takes about 15 minutes and buses depart every 15 minutes (10 during weekday peak periods). The fare is $2.50 ($2.75 during weekday peak periods).
To get to Sea-Tac Airport from Tukwila Int'l Blvd station you can either take the RapidRide A Line (takes about 7 minutes and you'll get a free transfer from the F Line) or Link (takes about 2 minutes, but unless you have the $5 ORCA card, there's no transfer credit so you'll have to pay another $2.25).
In total, the trip from Tukwila station (the Amtrak one) and Sea-Tac Airport should take about 35 minutes.
The other option is to ride Amtrak to King Street Station in Seattle. From there, walk across the street to International District/Chinatown station and ride Link to SeaTac/Airport station which costs $3.00 and takes about 37 minutes (plus another 20-25 minutes on the train).
Hope that helps!