Legend has it that fall walleye fishing is prime time for catching trophy deep walleyes and, in fact, bigger-than-usual fish of most species. Hard to argue with that. Seems like the Fall Coldwater Period consistently puts up oodles of outlandish 'eyes. Of such flurries are legends born.
Fact is, the fall scenario isn't simply one consistent mega-bite of big fish, but rather a succession of excellent conditions for catching trophies. The better you understand subtle changes in the environment and how they affect fish location, the more consistently you'll catch big fish.
Early fall kicks in right after the fall turnover, which is a period of turbulence in the environment marked by a mixing of the water, stirring of bottom sediments, expulsion of noxious gases, and a brief scattering and confusion of fish and fishing patterns. In essence, it's a tough time to predict fish behavior, when any choice or prediction may be as credible as the next. But once the water temperature and chemistry stabilize -- typically around 55F -- dependable fishing patterns tend to kick in.
At this point, assess the new environment and what it offers fish. Consistent oxygen and temperature levels from top to bottom remove any barriers to fish movement; walleyes can essentially be anywhere, shallow to deep. Previously uncomfortable warm, shallow water has cooled to a likable level, and some walleyes typically go on a hot bite across the tops of weedbeds, along shallow rocky shorelines, or atop reefs at night, and into the mouths of creek or river inlets. A shallow (flats) to moderately deep (primary drop-off) pattern definitely exists.
In southern reservoirs that reach uncomfortable midsummer water temperatures, shad and predator fish may have been forced out of coves during at least the latter part of summer due to local oxygen starvation. Now, both predator and prey have the option to return, often triggering an excellent bite on primary points at the entrances to coves. Even in some northern waters, a cooling of the shallows invites more walleyes to penetrate the shallows, at least briefly, in early fall.
Yet at the same time, big walleyes have the option to drop deep, into previously untenable lake zones due to summer oxygen depletion in the depths. But now, anywhere and everywhere is fair game. Deep Walleyes typically show less of a tendency to suspend and more likely hug the bottom in fall, unless they key heavily on suspended forage, such as in the Great Lakes. Even then, the perimeters of deep points and humps, often in the 30- to 50-foot-plus levels, attract fish of all sizes. Big walleyes using such spots typically intercept roaming ciscoes, smelt, or other open-water species at these levels.
This is when the bulk of autumn anglers typically wallop the fish. In essence, walleyes have just set up on classic deep fall structure and are ripe for the pluckin'.
A few weeks to a month into fall, however, a shift begins to occur as the water cools even further. Shallow weeds begin dying, reducing the attractiveness of many shallow areas. Baitfish like perch, often a primary walleye forage, begin dropping deeper, and walleyes follow. Shad begin to suspend deeper as well. When this occurs, expect a general deepening trend for the walleyes, too. Deeper patterns remain consistent or, in fact, improve as fall marches onward toward winter, while the shallow bite often begins to ebb -- at least during daytime hours.
By late fall, deep water offers a stable and safe food-rich environment. In most waters, expect most of the walleye activity to occur here, chiefly on classic fast-breaking structures dropping quickly into the main basin. Even so, notable flurries occur back in the shallows, typically triggered by influxes of forage into concentrated spots, such as:
River mouths -- Big-water walleyes, notably those of the Great Lakes, follow suspended forage into the current of inflowing rivers, chiefly at night. Yet even on modest-sized natural lakes, expect some river mouth activity at night.
Bay mouths -- In fertile prairie lakes, bullheads and salamanders returning from swamps into the adjacent soft-bottomed bays in late fall draw walleyes shallow for a moonlit feast. It's one of the best trophy opportunities of the year for shorecasters.
Fall-spawning forage -- Ciscoes spawn in shallow sand-gravel areas adjacent to the basin, typically in water temperatures at or below 40F. Walleyes and other predators may move shallow to feed on them at night.
Thus, in the grand scheme of things, you can experience both shallow and deep patterns all throughout fall. But when the opportunities across the walleye world are tallied, numbers indicate that odds go to fishing progressively deeper as fall deepens, in most places, most of the time. The wild cards are shallow forage movements and nighttime patterns, and if played properly, the resulting action can be wild, indeed. Ply them if you like, in areas where walleyes go when the sun doesn't shine. But for consistent daytime angling as fall recedes toward winter, deep patterns offer the most opportunities for success. That's as close to a sure bet as you'll ever encounter.