Rivers are different every day. Holes move. Water levels fluctuate. Clarity worsens with every rainfall and improves with every dry spell. Weeds grow well one year and seem nonexistent the next. It gets complicated, to say nothing of the fact that the water is moving across the landscape, creating an irresistible force that easily can demolish a carelessly captained craft.

Rivers are intimidating, which is why river rats are such happy people. Less pressure. And when river rats find fish, they find aggressive, biting fish. Consider walleyes in rivers. Flowing water quickly carries wounded and otherwise easy targets out of reach. Walleyes in rivers have only seconds to decide to bite or not to bite.

But all that intimidating stuff? Start slow and simple. Constantly scan the surface for snags or boils indicating shallow rocks. Use a flasher for quicker response time. For safety, have life vests, an anchor, and a sharp knife ready at all times. And remember that three observable factors affect the location and aggressiveness of river fish of all species: water depth, water clarity, and water temperature. Here’s a thumbnail guide to help you locate walleyes faster in flowing water from late winter through summer.

(1) River fish follow the path of least resistance when migrating. Walleyes migrate upriver in autumn to winter, stage, and eventually spawn in spring. During prespawn, they migrate from wintering holes to spawning areas in water temperatures from 34°F to 40°F. When walleyes move farthest during these migrations, they move at night, using darkness to cover them through the shallowest flats. When moving against current, they slide from current break to current break and swim upstream along the inside turn of riverbends, where current is greatly reduced. Distance also is reduced by following the inside bend.

(2) When the water is high, migrating walleyes tend to hug the banks, where current is slower. Important spots are shallow inundated floodplains and gravel flats on the inside of a bend, in relatively shallow water. Distinct drops from 2 to 3 feet or 3 to 4 feet on inside bends become critical in high, cloudy water.

Sediment and debris settle out quicker in eddies, giving walleyes a chance to breathe easier for a time, making floodplains and inside bends even more attractive as a place to hold. In cloudy water, walleyes tend to feel more secure in the shallows. In these conditions, put most casts on the bank and drag them into the water.

(3) When a river is low, walleyes still migrate in the slowest water possible, but the need for security outweighs the need to conserve energy. In clear water, the fish tend to settle down for the day in deeper holes, pools, and runs. The clearer the water, the deeper they hold when resting or feeding. But it’s important to note that river walleyes often rise to feed in 2- to 4-foot shallows during low-light periods (morning and evening) all summer.

(4) In all cases, walleyes migrating in rivers tend to stack up behind barriers. This could be something as obvious as a dam, or something far less obvious, like a long shallow flat no deeper than 2 feet. Where fish become obvious to birds, bears, and humans, they sense the potential for danger.

Faced with a long crossing through the shallows, most fish wait for the cover of darkness. If fish are moving throughout the day, quite a few can stack up below a long shallow stretch, below a rapids, or just downstream of a long, narrow neck where current increases dramatically. These barriers and others like them become key spots during migration periods.

(5) In the northernmost states and in Canada, resident river walleyes migrate from summer habitat to winter habitat during autumn. These migrations hit full stride when water temperatures first dip below 60°F. Walleyes in harsh northern climes tend to reach winter destinations before water temperatures drop below 42°F. They hold in deeper water during winter, looking for pools and holes with at least 20 feet of depth, and deeper where possible.

Walleyes leave wintering pools to stage near spawning habitat when water temperatures begin to rise in spring. Staging could be the wrong term, however, as walleyes may go directly from wintering to spawning without much activity in between. Walleyes spawn on rock-gravel riffle areas in 1 to 3 feet of water at temperatures ranging from about 43°F to about 49°F, usually while snow and ice still line the banks in northern states.

(6) Some populations of walleyes leave the river immediately after spawning to spend the summer in connecting lakes or reservoirs. True river walleyes begin appearing near summer habitat within the first week or so after spawning, and they live in and around current areas until fall migrations resume. The idea that walleyes rest or recuperate after spawning can be misleading, especially when they’re recharging their batteries with food so far away from spawning habitat that most anglers lose track of them.

(7) By the time water temperatures reach 60°F, most river walleyes are somewhere in the vicinity of areas where they spend the summer, unless their migration distance is extremely long. Summer habitat tends to be in classic riverine areas with lots of current and midriver structure like reefs, wing dams, or humps. As water levels tend to be higher in spring and lower in summer, walleyes change positions accordingly. Water temperature, water level, and water clarity have everything to do with river-walleye location during summer. For instance, walleyes may use increasingly faster water as the river warms.

But in years of high water, walleyes may not migrate as far upstream, opting not to buck the increased current. Key spots tend to be on inside bends, away from the main river channel, and even in backwater areas that walleyes seldom use in low water. In flooded rivers, walleyes often invade the floodplain, using living trees and bushes as current breaks.

In low-water years, the opposite tends to occur; walleyes push farther and scatter more. They also tend to remain in the river proper—the main channel and its immediate environs. River walleyes use midriver current breaks in low water. Key spots become reefs, rockpiles, bridge abutments, wing dams, humps, and islands that split or intersect the main current.

(8) Walleyes in rivers use current when feeding. Active walleyes seldom use slack water, but they position farther than trout or smallmouths from the fastest flows and on the back side of current breaks more often than those species. River current slows when the water’s low, and walleyes increasingly use the tops, sides, and even the front (upstream side) of reefs, rockpiles, and wing dams as water levels drop. Look for them in these locations, especially during low-light periods. During midday, the edges, head, and tail of deeper pools are key, especially in cold water.

(9) As mentioned, river walleyes are more aggressive than their lake-bound cousins, and cold fronts affect them less negatively as well. Hard-body baits—minnowbaits, suspending jerkbaits, crankbaits, and rattlebaits—tend to take bigger walleyes all year in rivers, even in water temperatures below 35°F. Live redtail chubs and other hardy river minnows on a rig or jig might outfish hard baits at any time all year, but they rarely produce bigger fish.

A true river “rodent” pays strict attention to water level, water temperature, and water clarity. A small rain shower in spring can cloud the river enough to make crankbaits (noise, thump, flash) more productive than minnows. That same rain shower can raise the water just enough to move walleyes around, from one feeding lane to a slower lane. And a shower can actually trigger an upstream migration.

To be consistently successful for river walleyes, forget every cliché ever uttered involving crankbaits and water temperature, especially during prespawn. Crankbaits and all those hard-body cousins (minnowbaits, jerkbaits) help locate aggressive walleyes quicker than livebait in almost any river condition.

Where prespawn bites are open to anglers on rivers—portions of the Upper Mississippi, the Rainy River, the Saginaw River, and in a host of other spots—staging walleyes can be found in heavy concentrations. It’s not hard to determine where; just find the flotilla of walleye boats. Vertical jigging with minnows is generally considered the “way to go” for river walleyes in spring. But trolling crankbaits through those concentrated schools consistently produces bigger fish. Much bigger. At this time of year, long, slim, deep divers in smaller sizes, like the Reef Runner Lil’ Ripper and Storm Deep Thunderstick Jr., connect with some real giants. Cranks are effective for finding walleyes fast in rivers.

Don’t forget plastics. During a hot bite, even in 32°F water, scented plastic tails may catch more fish per unit than minnows, meaning less down time changing baits, which translates into more fishing time, which means more fish caught. And you never know when the minnow supply will run out, especially on a long trip. Plastics like the Berkley Jig Worm, the Riverside Super Vee Tail, and the Mann’s Walleye Worm can save a trip.

Though the morning and evening bites are definitely best in summer, walleyes generally bite better at midday in rivers than in lakes. In spring, midday and evenings tend to be the best times to be on the river. But it’s always good to be on a river. Never boring. A river is an abstract, rolling puzzle, always changing. Every day. Change with it day to day, and the reward is consistent walleye fishing throughout the year.