On mountain trails with a loaded backpack for 2-4 day trips, I usually average just over 2 miles per hour. That includes a few thousand feet of mild (or at least short, <1000') ups and downs. If I decide to turn it on, 2.5 is easily within reach, provided the footing is good. Loose rock or ice means all bets are off, and more elevation cuts down on the speed. Trying to maintain 3mph on trails isn't much fun, and I backpack on vacation. Fun is what it's about. I average about 15 miles a day on the AT, for up to 7 days straight.

I find that I am better off continuing for an extra hour or so, rather than trying to set a land-speed record. Headlamps (or full moons) are great for night-hiking, which is an experience not to be missed. Thunderstorms, however, or rumors of cold beer at a road crossing on the AT, can twist my throttle.

Longest dayhike I've done (basically unloaded) was the Rachel Carson challenge in Pittsburgh. 34.6 miles, with over 10,000' of elevation change. The elevation profile looks like an EKG.

Toughest hike with a full pack was 19 miles in the Tetons, with 9,000' of elevation change. That hurt.