No, there is no JV for the wedge which is being negotiated. The wedge is left blank (no drilling) in Probe Corp Presentation, Slide 10. The western edge of the wedge is a straight line and the eastern edge is defined by the shore line (note the red nub at around 1500SE, this this the bay area which is 100%PRB.
The 50-50 JV is on the western side of the wedge. It looks like a square bracket with one end pointing to the east and the other end pointing south. The bottom end of this 50-50 JV contains part of the HGZ.
As I understand it, the other JV partner (the same lumber people) would have to fund 50% for the development of this property. If not it could be renegotiated to earn some royalty percentage leaving PRB to worry about the development of this portion. IR can provide more precise info on this JV.
Hope this helps.
goldhunter