Gamefish are not far behind. Rocks and wood absorb heat from the sun in spring and late fall, raising water temperature and igniting the food chain which boosts activity levels of fish. For the hunters, cover provides ambush points to wait for passing prey. For the hunted, it offers a safe haven from predators. This is critical in a watery world where who lives and who dies is a matter of survival of the fittest.
Weather is a factor while understanding the importance of cover.
Fish, like largemouth bass, will often dart to the safety of a thick weedbed in storms. Walleye anglers know to check timber after a cold front because walleyes will tuck in close and stay. This is known anyone who has tried to cast a jig into the thickest part of beaver cuttings or who has drifted over a flat strewn with fallen logs or boulders. You can't catch fish while tying. The easy way out is for anglers to stay away from snaggy, fish holding cover.