Rocks and boulders create hydraulic cushions within the stream. They are essentially resting/feeding spots for the trout. Think of rocks and boulders as a trout’s streamside Lazy Boy recliner. The most obvious location to target fish is immediately below (downstream) of a boulder, where it’s easy to see a soft water “pocket” form below the obstruction. These downstream pockets are easy for the angler to locate and target for their presentations. However, what if I were to tell you that there’s a better and more productive pocket? And it holds some of the best trout!
The pocket is, of course, on the front side of the boulder. The experienced angler knows this “secret pocket,” but many beginners fail to notice it. The front side “cushion” creates a primary feeding line, a place that offers protection, rest, and feeding opportunities. Think about it: the fish on the front side will have first dibs on available food, and the larger, more dominant fish know that (probably why they are bigger!) Smaller fish generally hold on the downstream side, feeding on whatever the big ones (the ones we want) pass up.
I’m not recommending that anglers disregard the downstream pocket – it can and sometimes does hold larger fish -- but the front side is worth at least a few passes. It is a primary feeding lie. It should be explored. Sometimes “the grass is greener” in spots we don’t think to fish. Fish it!