as for the differences between the differents geological models...

as for the differences between the differents geological models made in the respective April 2009 and Sept 2011 investor presentations, TRH just now advised me:

"...the September model was a revised version of the historical data due to new information. In Utah the drilling information must be given to the state for anyone to use after a period of time. Earlier this year we asked our geologists to update their data base for the new wells for which data has become available and also to review all the historical data to give us the best view available. The information in the September presentation comes from the new geology report with the new information..."