Fourth season on the Grand Mesa can be just about anything. Weather wise you can have 3' of snow or temperatures in the 70's or 80's. Also by fourth season all the elk will of been pushed one way or another if not both. Be prepared to drop off into canyons where other hunters won't go and if it stays dry like it is now hunt near water.
I'm new to Colorado big game hunting myself but a couple of basic things you might want to look into doing to have a successful hunt: Scouting and learning the area is huge. Get a good pair of binoculars and a spotting scope if you can and try to figure out what the elk are doing before your opening day. Also, shoot your rifle. I don't know how many hunters screw up and loose game because they don't sight in their rifles and dont shoot free handed. Get a rest on your knee, a tree, or a shooting stick. Lastly, since your new to this I hope your going with someone who has gone before and guide you a little bit and help you with all the work after you shoot one.
Others have offered up a sighting of roughly 2 inches high at 100 yards as a good sighting scheme. In my own experience I have come to favor a sighting of 3.5 inches high at 100 yards. This allows for the individual to hold dead-on (directly in the middle of the top and bottom) the animal out to roughly 350 yards.
Magnum calibers such as the 7mm Remington and 300 Winchester will extend this slightly. At 400 yards I hold directly on the backbone of the animal. The drop at this range allows the...