I just plotted the entire trail as a walk from the portal trailhead to the summit and got 9.9 miles on Google maps, I know for a fact that the figure is 11 miles, is Google maps wrong?
https://imageshack.com/i/p9fwr7t9jhttps://www.google.com/maps/dir/36.586903,-118.2401676/36.5784934,-118.2924641/@36.5745138,-118.2650548,15.5z/data=!4m2!4m1!3e2
Infact, I am plotting points on OSMAnd, which is an offline map application for Android which I plan to use on the trail and it the point between the turnoff onto the Mt. Whitney Trail to the John Muir trail and the summit seems too short on Google Maps.