Seattle–Tacoma International Airport

Seattle-Tacoma — Sea-Tac — is the Pacific Northwest’s main airport and Alaska Airlines’ home base, with a large Delta operation alongside it. It is a single terminal, but part of it works in a way that surprises first-timers: some gates are out in detached satellite concourses reached by an underground train.

The layout

The main terminal has concourses A through D directly attached, plus two satellite concourses — North and South — that sit apart from the main building and are reached by an underground automated Satellite Transit System train. If your gate is on the North or South satellite, you ride the train out and back; it runs frequently, but factor it into your timing, especially on a connection. Most flights stay within the airside area, so transfers are generally straightforward.

Getting into Seattle

The easy, traffic-proof route is the Link light rail (1 Line). Its station is a short walk from the terminal via the parking garage, and it runs into downtown Seattle in around 40 minutes for a low fare, continuing north through the city and to the university. The airport is about 21 km south of downtown, so a taxi or rideshare is a longer, pricier trip, and Interstate 5 can be congested — the train usually wins for downtown.

Worth knowing

Sea-Tac is busy and space-constrained for its traffic, so security lines and the walk to a satellite gate can eat time; arrive with a margin. The Pacific Northwest weather is rarely a hard stop, but low cloud and winter conditions can slow arrivals. If your gate is on a satellite, don’t leave the train ride to the last minute — that underground hop is the part people forget.