Add elevation to this. Reds Meadow is already at 7,500 ft. I believe the 4k ft mentioned is net climb for the hike, not necessarily a peak elevation of 11,500 ft., though passes in the region certainly rise above 10,000 feet, and peaks top 14,000 (Whitney).

With a full pack, unacclimated, making 10+ miles is a pretty good day. 13 miles outrunning a forest fire is respectable.