Here in Ohio the "toughest" hill is only 0.5 miles at 13% average grade.

Now i'm a big guy. Two hundred and thirty pounds big. I ride up that silly thing with a 53/39 and 12-26 cassette. I average about 5mph up it.

So my conclusion is that the hill you are talking about is completely doable by most people that can ride a bike, are lighter than me, and have a triple.