Sit on the Left side of the plane for the best views on flights from Ontario to Denver. Left side delivers the San Gabriel Mountains on departure and the full Rocky Mountain Front Range panorama on approach — both are the defining visual payoffs of this route. The right side offers only valley and plains views for most of the flight.

During takeoff from Ontario International (ONT), sit on the Left side for the best views. ONT typically departs east on runway 26R/08L. An eastbound departure on runway 08 puts the San Gabriel Mountains directly off the left (north) side as you climb out, with the dramatic front face of Mt. San Antonio (Mt. Baldy) at 10,064 ft filling the view. The urban sprawl of the Inland Empire and San Bernardino spread out below to the right. Notable sights include: Mt. San Antonio (Mt. Baldy), San Gabriel Mountains front range, San Bernardino Valley urban grid, Ontario city grid below.

When landing at Denver International (DEN), sit on the Left side for the best views. DEN typically lands from the east on runway 16R/34L or approaches from the west on runway 35L. On the most common westbound approach to DEN, aircraft approach from the east and the entire Front Range — including Longs Peak, Mt. Evans, and Pikes Peak — lines up along the left (south and west) side. The Rocky Mountain wall is one of the most dramatic approach views in the US. Notable sights include: Rocky Mountain Front Range, Longs Peak, Mt. Evans, Pikes Peak (distant to south).

The flight from Ontario International (ONT) to Denver International (DEN) takes Approximately 2 hours to 2 hours 15 minutes.

The flight crosses the Mojave Desert, then the Colorado River near Needles, then the high desert plateau of northwestern Arizona and southwestern Colorado including the Kaibab Plateau region. The route then crosses the San Juan Mountains of southwestern Colorado — a rugged snow-capped range visible from both sides — before descending across the flat San Luis Valley and the Palmer Divide onto the Denver plains.