I did some quick, crude calculations and found: the average rate of ascent from the North Col up to the summit (a horizontal distance of approximately 2.5 mi) is about 2500 ft/mi.
Breaking this distance up into two:
- the first half (from the North Col up to the point where the northeast ridge portion begins) has a rate of ascent of about 3100 ft/mi.
- the second half (the northeast ridge portion which consists of the first, second, third steps and ends at the summit) has a more moderate 1900 ft/mi.
I guess I never realized the actual steepness of this route. This really puts the effort required to climb the mountain, especially at altitude, into perspective.