All Aboard the SEA Underground (2024)

Ciceron, Dianne

Late to your gate? Don’t let a mad dash across the terminal derail your travel experience. Sometimes the quickest way to your destination at Seattle-Tacoma International Airport (SEA) is to go underground. SEA trains have always had the ability to get you across the terminal in a snap and help you access the N and S Concourses, and now the airport’s train system has a new name.

Allow us to reintroduce the airport’s train system as the SEA Underground! Hop on board and mind the gap with these tips and tricks. Next stop: SEA Underground!

Fast Facts on SEA Underground:

• Know before you go: Each airline leases different gates around the terminal. Depending on your airline you’ll be able to narrow down where you need to go to board your flight! Alaska Airlines flies out of C, D, and N gates.Delta, United, and almost all international airlinesfly out of the S and A gates. See a full list of airlines and their gate assignments
• Get to all gates: The A, B, C, and D Concourses are all connected and you canwalk or take the train to any of those four.To get to the N and S Concourses, you’ll have to take SEA Underground since they’re not connected to other gates
• Made it through security? Find the nearest train station to you.Checkpoint 2 is the closestcheckpoint to the S Train Loop while Checkpoint 5 is the closestto the N Train Loop. Or use our interactive map for step-by-step directions!
• Hop on for a quick ride: In a rush? Even though you can walk to each gate outside the N Concourse and Concourse S, you can easily take a train to get to your destination quicker! Each train ride is two to five minutes long. A timer on top of each train estimates the arrival of the next train
• Don’t exit by mistake: When exiting the train, if you’re continuing on to your flight, make sure to steer clear of all baggage claim signs! If you pass an airport employee in front of a desk on the SEA Underground level, you’re more than likely going to exit out of the secure area. Need to exit?Head to the Concourse Sor N for two options to exit from the secure area

Ride the rainbow

The SEA Underground consists of three lines andeach is assigned a different color — the Blue Line (South Train Loop), the Yellow Line (Shuttle train between A and D stations), and the Green Line (North Train Loop). The lines are easy to identifybythe corresponding color on the walls next to and behind the stationdoors (And don’t worry!SEA is working on adding more signagesoon!) In the meantime, here’s a quick cheat sheet:

Underground amenities

Learn what you can find at each SEA Underground station. For more guidance, use our interactive map or download theflySEA app.

Station and Train Line	Amenities
Blue Line(South Train Loop) Yellow Line(Shuttle train between A and D stations)		Sensory Room The Interfaith Prayer and Meditation Room Exit to Baggage Claim
Blue Line (South Train Loop)		Art
Blue Line (South Train Loop)		Mamava Nursing Pod Pet Relief Area
Green Line (North Train Loop) Yellow Line (Shuttle train between A and D stations)		Mamava Nursing Pod Pet Relief Area Exit to Baggage Claim
Green Line (North Train Loop)		Restrooms Water Refill Station Pet Relief Area
Green Line (North Train Loop)		Art

Want to learn more?

• Check this out:User’s Guide to the Trainfor more tips on theSEA Underground
• Here to help:Information boothsstaffed by volunteers are located at both the A and D train stations. Theycan help point you in the right direction
• More art:Learn more about artwork atSEA Airport
• Maps andapp: For more guidance or information on any location, visit our interactive map or download the FlySEA app