Fish have three basic urges. First, each species requires acceptable habitat – a safe territory with appropriate light, temperature and dissolved oxygen content. Secondly, fish need a ready supply of food. And third, fish must have the opportunity to reproduce and perpetuate the species. As an angler comes to understand the habits and behavior of his quarry, he can more easily locate fish and catch them.


Environment and instinct dictate a fish’s behavior patterns. The cold-blooded fish seeks a comfort zone, preferring to locate in a temperature layer that also provides safety. For example, the bronze mottled and barred coloration of smallmouth bass blends well with underwater rock bars and shelves. Rocks provide these bass with camouflage (safety). Rocks are also home to one of the smallmouth’s favorite foods, the crayfish. Not all rocky areas in a lake will hold smallies, however, a savvy smallmouth angler looks at a fishing map and finds underwater rocks, then fishes only those areas suitable for bass. Smallmouth may find rocks in the shallows too warm and bright, and rocks in super-deep water devoid of oxygen. A map’s contour lines bracket rock areas in between these two extremes–the best places to fish.

smallmouth bass over rocks

Food Supply

Fish must eat regularly. Once a fisherman knows the basic diet of the species he seeks, he can locate areas where that food supply exists. Muskellunge prefer suckers in their diet, particularly the common white sucker. These suckers prefer flowing water.

Since fishing maps designate creek inlets, the well-prepared muskie
angler will look at a map and find shallow bays fed by creeks or small rivers. These areas are likely to attract suckers, and therefore, muskie. Casting brownish-gray sucker-pattern plugs that mimic the forage will increase his chances for success. A muskie outing based on mapped information is much more productive than random searches.

creek inlet fishing hot spot
A creek inlet marked as a fishing hot spot on Fishidy’s map


Every species of fish has a specific set of criteria for carrying out its reproductive chores. A popular fish all over the country, the white bass, spawns when water reaches 58 degrees. Schools of whites (also called sand bass in some parts of the country) seek gravel bottoms in 6 to 7 feet of fairly clear water with either a measurable current or significant wind action to successfully reproduce. If you fish for white bass in any of the nation’s large reservoirs, you will want to fish when the water temperature and conditions are right.

Water Temperature Preferred by Species

Water Temperate Preferred by Species

Springtime white bass anglers should look for shallow contours–but which ones? A map will tell you. Reservoirs are fed by a series of rivers and creeks, each entering the main body of water from its own cove. Most of these coves have water shallow enough for white bass to spawn. Since these bass want flowing or wind-swept water, if you find creek arms with significant flow or areas wide enough to be affected by wind, the fish will likely be there, not in small wind-protected or inlet-free coves.

Other Factors

Finding fish is not always as simple as relating your search to comfort, food supply and spawning requirements. There are several other factors that play important roles in the process. If, for example, you know that largemouth bass are most comfortable and active in water at 75 degrees, that does not suggest that you will catch largemouth everywhere you find water that temperature. You have to target water that provides bass with other features. If one of those areas is also 75 degrees, you stand a good chance of finding Mr. Bucketmouth.


Structure is more bassy than open water. Why? Structure provides bass with protective cover. Structure leads bass to food. Structure may provide shade from the rays of the sun. Open water affords none of these opportunities for bass. What is the best way to find structure? Look at your fishing map. The legend has symbols which represent various types of structure. Check all these marked areas and you are most likely to find largemouth bass.

bass under lilypads

Fish relate to many underwater characteristics. Maps identify these features. California’s Lake Sonoma is a typical, structure-rich reservoir. Sonoma has off-shore weedbeds which at certain times are red-hot bass fishing spots, but, bass are not always in the weeds. They find plenty of cover and food scattered among the lake’s flooded timber. Top quality fishing maps highlight flooded timber and lead you to bass when weeds are not productive.

Docks and piers are good examples of fish-holding structure. Sharp drop-offs, weed edges, turns in a creek channel, intersections of two creek channels, submerged points, off-shore humps, mud flats, rock reefs, brush piles, man-made fish attractors, abrupt changes in bottom composition, and a myriad of similar underwater features are magnets for fish. Fishing maps identify these features. The more you study a map, the more fish you will have the opportunity to meet on the end of your line.

structure on fishing map

Light Penetration

Light is another factor in determining fish location. Generally, fish avoid bright light. Light penetrates clear water much more intensely than cloudy water. Fish tend to frequent deeper water in gin-clear lakes compared to lakes with water the clarity of coffee mixed with cream.

Since light penetrates to greater depths in clear water (above) fish tend to suspend deeper than they normally would if the water was murky or stained (below).

Fish usually prefer shade to unshaded areas. They can avoid light in two general ways, either by moving to deeper water where light penetration is reduced, or by moving into the shade of an overhanging object such as a dock, tree or boathouse. Fish often avoid bright light by burying themselves at the base of thick weed growth like coontail, milfoil or hydrilla.

Maps help anglers take advantage of a fish’s tendency to seek cover and shade. Since maps have a directional arrow (pointing north), fishermen can predict the shaded sides of the entire lake and shaded areas of specific structure. You can determine, just by looking at a map, if an underwater tapering point off the northeast side of an island will be sunny or shady at 3:15 p.m.

The Food Chain

A fish’s position on the food chain is significant in how it relates to cover. Panfish like crappie and bream seek cover much more readily than northern pike, muskellunge and huge bass. Panfish are lower on the freshwater food chain, while the pike family is at the top. Since muskellunge have been known to attack anything that moves, this opportunistic fish is found in many different locations–from shorelines looking for ducklings to deep offshore walleye reefs. Crappie feed on small minnows and insects and do not stray too far from these important foods. Crappie will school near minnow-holding structure like weedbeds, brush piles, fallen trees, and shoreline riprap and docks.

Study a fishing map to find areas likely to hold the preferred food of the species you seek. You will not fish randomly or “blind” when you coordinate your position and lure (or bait) presentation with a fishing map.