The Lee Hill taproom had on their Lee Hill Vol. 3 barrel-aged series. It was an imperial stout that was aged for 6 months in a barrel and then keg aged for another 6 months.
At the Flatirons taproom, the special beer was a 3 year old Barleywine.
For more GABF specials at Upslope Brewing, http://upslopebrewing.com/blog/