The printable 2015 Harvest Calendar is available for download and home printing! Or you can pick a copy up at the Mount Rogers Naturalist Rally or the Independence Farmer's Market.
I did not harvest this plant, but the friends that did were told what they had by a native to these mountains. That person claimed that branch lettuce was becoming rare due to over harvesting. It can be eaten raw in a salad, or cooked in bacon fat.