There's been discussions where the "next" airport should go in the Seattle region, and the consensus is that nobody wants it. The State Legislature created a commission to try and identify some potential sites, but the public backlash was so great that they ended up submitting it's final report with no actual recommendation.
One of the interesting ideas (that was proposed even back when SEA was adding it's third runway) is to run high-speed rail to Moses Lake Airport in Central Washington and just expand there. I'm doubtful it happens, since that means building a major airport _and_ a new train.
One of the interesting ideas (that was proposed even back when SEA was adding it's third runway) is to run high-speed rail to Moses Lake Airport in Central Washington and just expand there. I'm doubtful it happens, since that means building a major airport _and_ a new train.