Doing a fall trip to DC and Gettysburg around Columbus day this year (last year the WV recommendations hit the jack pot........got some great pics...WV 72 sucks though). I am Interstating it to DC. Any ideals about southern PA from Gettysbug to the Somerset area. Also is southern PA usually at peak around this time? I know it's hit and miss every fall but what's the average.
You could take either US 30 from Gettysburg to Jennerstown then PA 985 (old US 219/old PA 6) south to Somerset. Plenty of things to see along the way besides the Flight 93 Memorial (http://www.pahighways.com/features/shanksville.html) and Quecreek Mine Rescue (http://www.pahighways.com/features/quecreek.html) site, there is the LHHC's Roadside Museum (http://www.lhhc.org/roadside.asp). Or take US 30 to PA 31 which will take you right into Somerset.
That should be around the middle to end of the peak up in the mountains. In the lowlands where I live, the peak is closer to the beginning of November.