I have hunted both elk and mule deer with a T/C Contender in .357 Herrett and 7-30 Waters and have had a lot of fun doing it. The longest shot that I have taken was on a 3x4 mule deer with the 7-30 Waters with a 120 grain bullet at 2900 fps and he droped in his tracks. One of the elk that I took with the .357 Herrett droped in her tracks at a little over 100 yards. I have also taken two bull elk with the Herrett with no problems and one with the Waters witch took a follow up shot but it really wasn't necessary.
So if your friend is hunting with a .308 in one I would tell him not to wait until the last day but to start out from the begining with it and enjoy it.
One of the most important components of deciphering a new hunting area is distinguishing between the summer and winter ranges for the game that you plan to pursue. Without knowing this you cannot make reliable assumptions about where the game will be come opening day. Knowing these areas will allow you to take the current weather (as well as the past couple weeks) and apply that to the landscape and make an educated guess as to where you might find that big buck or bull.
There are a couple ways...