Sit on the Right side of the plane for the best views on flights from Boise to Seattle. Right side wins overall. While left is better at takeoff for the Snake River Plain view, the right side delivers the dominant spectacle of the flight: the Cascade volcanoes including Mount Adams and Mount Rainier appearing progressively through the cruise, and then the stunning Puget Sound and Seattle approach. Mount Rainier in particular is a right-side feature as you descend from the southeast.

During takeoff from Boise Air Terminal (BOI), sit on the Left side for the best views. Boise typically departs northwest on runway 28L/28R, so the left (south) side gives you a clear look back at the Boise Front foothills and the Snake River Plain spreading east. The right side faces north toward less dramatic terrain on climbout. Notable sights include: Snake River Plain stretching east, Boise foothills and Table Rock, Treasure Valley agricultural patchwork, Owyhee Mountains to the southwest.

When landing at Seattle Tacoma International (SEA), sit on the Right side for the best views. SeaTac primarily lands on runways 16L/16R heading south, meaning the approach comes from the north over Puget Sound. The right (west) side gives you Puget Sound, the Olympic Peninsula, and Elliott Bay with downtown Seattle clearly visible. Left side faces east toward the Cascades which are also excellent but the water and city view on the right is the classic Seattle arrival. Notable sights include: Elliott Bay and downtown Seattle skyline, Puget Sound, Olympic Mountains across the water, Vashon Island below.

The flight from Boise Air Terminal (BOI) to Seattle Tacoma International (SEA) takes Approximately 55 to 70 minutes.

The flight tracks northwest across the Columbia Plateau in Oregon and Washington, crossing the Blue Mountains as a wrinkled brown upland visible below. The Columbia River appears as a wide silver ribbon cutting through the plateau. As you approach Washington state, the Cascade Range builds on the right horizon with Mount Adams appearing first as a broad snow-capped cone, then Mount Rainier dominates — the largest glaciated peak in the lower 48 — sitting prominently to the right during descent. The Yakima Valley's irrigated agricultural geometry is visible below before the terrain rises into the Cascades.