Every summer Mother Nature remodels the rivers that feed into Lake Erie providing new places for steelhead to hang out during their runs upstream. Sometimes the changes are subtle. For example, a pocket at the end of pool on the Rocky River under a tree shifted downstream about five feet. Once I figured out that change, two fresh fish quickly came to the bank. I expect the fish liked it when the pocket was farther upstream and the tree provided more protection from anglers.
Sometimes the changes are dramatic. Heavy floods washed a lot of gravel out of prime holding spots on Elk Creek leaving nothing but flat shale bottom behind. Long stretches of flat shale are like fish deserts. There is no gravel or boulders to create pockets or breaks for the fish to get out of the current. Stretches that once held dozens of fish are now barren. Perhaps somewhere downstream there are new holding spots filled with gravel from upstream. If those spots exist I haven't found them yet.