The link above is to a Rigzone article discussing the April
2013 USGS Bakken/Three Forks estimate, which was referenced by Robert Rapier at
The USGS slide presentation can be found at
and click on the slide presentation pdf link near the bottom of that page.
I had been ignoring the "undiscovered" and was
incorrectly interpreting the estimate as the full TRR, until I read the
following in the Rigzone article: