As a solo hiker, my average is probably 10-15 miles per day. I've backpacked about 60 or 70 miles of the OHT and I would say that 12 is a comfortable day although I would sleep very well. As far as the elevation profile for his hike, just glancing at Tim's guidebook, it looks like it ranges from 900 to 2380 feet. I could be a little bit off on the low end, but 2380 is the highest point on the trail. I don't think he made it that far.

I've backpacked to the falls at Hemmed-In-Hollow at least 10 times and would have no problem with backpacking another 8 or 10 miles the next day.

In Tim's guide for this trail (Fourth Edition, page 17) he states the typical hiker in great shape can do the trail in 14 days (165 miles). That would come to roughly 12 miles a day.

I'm waiting to hear the rest of the story on this one...

Jon