I haven't explored the area, but saw this blog post not too long ago when I was looking at some places in the Eastern Sierra to add my to-do list. I don't believe they did Tunnabora, but they hit some other spots in the area, and utilized the George Creek drainage.
http://peaksforfreaks.blogspot.com/2013/07/mt-carl-heller-barnard-east-mt-barnard.html Chris
