I've travelled that Great Circle route many, many times; often in winter heading to Denver for hill-sliding fun.
I look out the window of the plane, at 36000ft, and gaze down on the vastness of the white mountain ranges below me.
I have no idea of scale.
What height are those peaks, those ridges?
Has any human ever climbed them?
They seem countless in number, ridge after ridge of impenetrable snow-covered mountains, vastly remote from anywhere.