Smallmouth Structure
Fisheries biologists and river guides tout the number of catchable size fish per river mile, but that type of statistic is meaningful only when comparing one river to another. More fish per mile of river means more opportunities to catch fish. That statistic gives no clue where the biggest fish swim in those miles. But make no mistake, size matters. The biggest fish take the best feeding lanes, and after they eat, they retire to the places that offer the most shelter and security to rest and relax until it’s time to hit the food trough again.
Smallmouths are structure-oriented ambush feeders, and river fish are lazy. Reluctant to fight against the main current, they linger where some form of structure provides a current break. They hang out in the soft water, waiting for the flow to convey food to them. To find fish, look for a combination of fish-holding structure—broken rock or cobble—directly adjacent to the river current.
Moreover, big smallmouths love ledges, both shallow and deep. Shallow rock fingers running perpendicular to the bank undercut rocks where fish await. A frothy current running over a shallow ledge brings food and provides security from overhead predators. Deepwater ledges are transition zones. The big boys and girls suspend in the deep water until they spot some unsuspecting edible item, usually a crayfish or baitfish, swimming along in the shallow water.
Serpentine rivers offer two lies—each fishing best under different lighting conditions. The outside bend of a curve is always deepest with faster current that scours the substrate away, leaving only larger rocks and boulders. The inside edge of every curve is shallower and slower. Smallmouths use rocks in the outside bend as shields to break the current, keeping a watchful eye for food flowing past. Target the outside bend in bright light. Under low-light conditions or increased turbidity, fish move into the shallows of the inside bend, looking for baitfish or crayfish. Resist the impulse to wade without making a few casts in the pocket where the current first slows.
Find an undercut bank with a modest current flushing food into it, and you’ve hit the smallie trifecta of food, shelter, and security. The challenge is to get the fly down to the big fish before a smaller fish grabs it. Combat the pesky little guys by using a more heavily weighted fly that quickly drops into the big fish zone.
Finding the biggest smallmouths in still water can be a challenge because fish must move to find food. The bigger the fish, the more it travels, both in its daily search for food and its seasonal habits. Structure is still a key to locating fish. Water temperature, water clarity, and wind direction are additional factors in determining how deep the fish will be holding and where they will be in relation to the structure. As water temperature increases, the fish move up in the water column until they get overheated and drop back into cooler water. In clear water, look for the fish to be holding on the deep side of ledges and points. Conversely off-color water provides protection from airborne predators and excellent ambushing opportunities for big smallmouths in the shallows. When the water is dark, run the fly as close to structure as possible because that’s where the fish will be. Wind flowing over an obstruction will drive food to the leeward side with smallmouths facing the wind.
The Last Cast
There are a couple of ways to approach trophy smallmouth fishing. One is to flog every bit of the water until your muscles fatigue and maybe catch a fish or two. The other is to pay attention and try to answer “why” questions.
Big fish live in prime lies, but not every prime lie holds a big fish. Before leaving a spot where a big fish was caught, take a close look at the lie to determine why the fish was there. Did the current funnel food into the lie? Was the fish on or near a spawning site? In late summer’s elevated water temperature and lower dissolved oxygen, was the fish near the head of a riffle or run? If you’re fishing still water, was the fish near a transition zone that offered shallow water for feeding with the security of deep water a few tail swishes away? Try to construct an accurate set of big-fish conditions that will allow you to recognize those conditions elsewhere.
Remember, smallies don’t cut and run like trout. Instead they square their shoulders and challenge the angler to an alley fight. It’s important to match the weight of the rod to the weight of the intended quarry. A 9-foot, 7-weight rod is strong enough to withstand the bullying fight and subdue a large fish without overtaxing it. The rod can also cast two flies into the teeth of the wind or make the long casts sometimes necessary when fishing pressured waters.
Smallmouth rivers and streams have three depths that need to be covered: the bottom of pools, the intermediate shallows, and the surface. If your budget allows the purchase of just one line, opt for a weight-forward floating line. If you then need a fly to sink to greater depths, adjust the leader length, add split shot, cast upstream, and let it sink, or use a combination of these tactics. A clear intermediate or Type III sinking-tip line covers the upper five or six feet of water. A full sinking line completes the arsenal. For deepwater lake fish, a short T-14 head attached to a full sinking line is a good method of reaching them.
When the early-season water temperature hits 55 degrees, the sexually mature males begin to hunt spawning sites while the females, heavy with ripening eggs, remain in deeper water. Now is the time to catch fish in their prime and at their heaviest. Now is also the easiest time to find concentrations of fish, as they will be in the vicinity of good spawning areas, typically cobble substrate.
Come September and October, when most fishers, and certainly most bass fishers, put away the rods and turn to football and hunting, the bass are gearing up for a fall feeding frenzy in an effort to get fat enough to survive winter. A dropping water temperature keys the bite. The first wave begins at 60 degrees, with another and final wave at 50 degrees. The fish cycle back and forth within the water column, retreating to deep water at night, then moving shallow as the sun warms the water during the day. Most of the available aquatic insects of interest to smallmouths have already hatched for the year. The fall food supply consists of mature baitfish and crayfish, so the flies should be sized accordingly.
Anglers catch big fish every hour of the day. However, fishermen catch more big fish during the low-light conditions of early morning and evening, trending into full darkness. That makes perfect sense in waters where the predominant forage is crayfish because they are most active and available to smallmouths in low-light conditions.
Fish at night where regulations allow. In parts of the country where summer air temperatures turn still waters into saunas, get on the water when the sun drops below the horizon. The water temperature will begin to cool, and fish that remained deep all day begin to move up.
Lastly, don’t be afraid to fish in bad weather. Wind and rain can increase oxygen levels in water and trigger a nice feeding bite. As an added bonus, even on pressured waters, you’ll more likely have the water to yourself.
Forget the rule that you should never leave fish to find fish. Stillwater smallmouths tend to school by size. The trophy fish rarely hang out with their little brothers and sisters. Schoolies are fun to catch, but leave them to search for the big girls.
One of the joys of fly fishing is learning something new. It’s been said that if you ever stop learning, you might as well stop fishing. Figuring out where the big fish live is a terrific reason to keep fishing. See you on the water.
David Paul Williams is a writer from Bellevue, Washington. His latest book, Fly Fishing for Western Smallmouth, contains more information on how to catch trophy smallmouth bass.