1st week is best for chance of them still being volcal,and they have not been pressured. The trade off is that there are usually more hunters the first week, and after a day or two the elk scatter and head for cover. If you wait until the end, you will have less competition, and I have noticed the elk starting to come back out of the deep dark holes later in the season. You may get the help of snow later in the season, making tracking easier, and if enough falls the elk may move to lower elevations, concentrating their numbers, but that depends on the area you hunt and the weather.