If your father wants to hunt hard and get a good sized elk, I would say the Walla Walla Watershed. But the canyons are really really deep & Steep. You will see many bulls and if you hunt hard you will succeed. If your father can't get around deep and steep canyons then I would say draw for Yakima area.
I got drawn for the watershed with 2 point and another guy got draw the same year with 1 point, my dad got drawn the next year with 12 points...So as far as point wise it is the luck of the draw