Where I live in the summer I have a 1 mile climb with an average 12% and a short section of just about 18%- so pretty similar conditions to what you describe. I find that managing anything close to 50-60 rpm's for most of the climb is pretty much the only way I can get up it. Granted there is a section where it goes level for about 200', which gives me a chance to up the RPM's and stay loose. You seem to be doing the right thing by keeping your cadence as high as possible for the conditions you are in. Flat stretches 90+ rpm's is great. Downhill wind it out to 120+ and up hill about 1/2 that seems about right to me.

Where in Western MA are you?- my house is in Becket.