He may not return to it each morning, however, and may use other areas as well. Because the bull by nature seeks the most secure hiding spot in his timbered domain for his nest, he'll feel safest in the thickest cover he can find. I've seen animals in places where you'd think a rabbit would have trouble getting through. Since plenty of food must be close at hand, a lair will be in a place where enough sun strikes the forest floor to encourage the growth of grass and underbrush preferred by elk. This rules out old-growth forests with canopies so tight that no browse can grow.
Water is also essential, requiring a location next to a creek, spring or seep.
With both food and water available, the bull needs only security cover to maintain a comfortable existence. He's probably been fired upon at least once and is thoroughly respectful of hunter presence in the woods. He's learned that people are far less abundant in certain parts of his forested domain, which is precisely why he's learned to stay put in such places. Practically every nest I've found has an escape route that a smart bull can use to quickly exit his sanctuary if he's discovered. This route typically leads to busted country with plenty of deadfalls, heavy timber and few trails used by humans.