Second, the conditions an angler can encounter on a freestone stream can vary enormously depending on time of year and the amount of snowfall the previous winter. Tail waters can vary hour by hour depending on the volume of water released from the dam. I have fished tail waters where I could wade across the entire stream without getting wet above the knee and only to find it completely unfishable after returning from dinner due to a release from the dam. Another factor in freestone stream fishing is insect life. Insect will be less abundant than in spring creeks.
Conditions make life harder for the bugs as well as the fish and plants.
In many ways this can be a good thing for the angler. In a spring creek with its rich and varied insect life the fish have a veritable smorgasbord of food to choose from. An angler must be more careful to match the types of insects in the stream and the possible selection can be huge. This makes preparation of the fly boxes a little simpler. A fisherman I know regularly fishes a freestone stream with a fly box containing only eight patterns in three sizes each.