Sit on the Left side of the plane for the best views on flights from Washington to Denver. Left side wins at both ends of the flight. At takeoff you get the Blue Ridge and Shenandoah Valley; during cruise over Kansas and eastern Colorado the left side faces slightly more toward the Rockies as they come into view on the horizon; and on approach to DEN the left side delivers the full Front Range panorama with the Denver skyline in front of it.

During takeoff from Washington Dulles International (IAD), sit on the Left side for the best views. Dulles typically departs westbound on runway 19R/01L or uses runways oriented northeast-southwest. On a westbound departure climbing out, the left side faces south and picks up the Potomac River, the Virginia piedmont, and the Blue Ridge Mountains as the aircraft banks toward its westerly heading. The right side looks north toward suburban Maryland with less dramatic geography. Notable sights include: Potomac River valley, Blue Ridge Mountains (visible to the southwest), Shenandoah Valley, Dulles Access Road corridor below.

When landing at Denver International (DEN), sit on the Left side for the best views. Denver International sits northeast of downtown Denver, and aircraft typically approach from the east on runways oriented roughly north-south or northeast-southwest. On approach from the east, the left side faces north and northwest, giving a direct view of the Front Range — including Longs Peak, the Indian Peaks, and the Denver skyline against the mountains. The right side looks south and southeast over the flat eastern plains with little of interest. Notable sights include: Front Range of the Rocky Mountains, Longs Peak and Indian Peaks (northwest), Denver skyline, South Platte River valley.

The flight from Washington Dulles International (IAD) to Denver International (DEN) takes Approximately 3 hours 45 minutes.

The flight crosses the Appalachian ridges briefly after departure, then transitions to the flat Ohio and Indiana farmland, followed by the Missouri River crossing near Kansas City, then the vast Kansas wheat plains. The terrain remains flat until the Colorado border, where the high plains begin a subtle rise toward the Rockies. The Front Range becomes visible from the left side roughly 100-150 miles out as a white-capped wall on the western horizon.