A depth finder (a k a fish locator) is a handy angling tool when looking for fish-producing areas of a lake or pond (especially man-made impoundments). Observing the land surrounding such water is a pretty good substitute.

It is difficult to use a depth finder without a boat. However, being able to read “the lay-of-the-land” makes it possible to get a mind’s eye view of the bottom of a lake, pond, or other man-made impoundments, while standing on the shore. It will be just as graphic--perhaps more so--from a position on the water.

The importance of the concept is based on the age-old theory that bass and other game fish (especially those of the sunfish tribe) spend most of the daylight hours in deep water. But this thinking also suggests that when fish go on the feed they move to other parts of a lake or pond, including shallow water.

Just as some species of wild game travel well-established trails, fish seem to do likewise. And, if my angling experiences, and those of the late Rocky Haulk, one of my boyhood angling mentors, can be used as a yardstick, the bottom of a body of standing water often is reflected in the lay-of-the-land adjacent to the impoundment.

“You can tell what the bottom (of a pond or lake) looks like by looking at the surrounding land,” Rock once told me, as we fished a Jackson County pond.

We had parked his old flivver near the shore of the pond and grabbed our bait-casting outfits to get after the bass. I walked to the shore and started casting with no particular plan. Rock walked the shore of the pond until he came to what he called a “dry gulch” (his terminology), a low spot in the gentle hillside where water from rain flowed into the pond. Ravine might have been a better word for it. 

His first cast went straight out into the pond from this low spot on the bank, and it was rewarded with a nice bass.

When I asked Rock why he had gone to that spot to try his luck, he unveiled his theory.

Before the pond had been impounded, that dry gulch had extended all the way to the other end of the field that now was a pond. And it still was there, he said, although it was covered with a few feet of water.

“When bass move, they travel the lowest spot,” Rock said.

Over the years I have fished many ponds and small lakes and have come up with some refinements of Rock’s theory and angling methods.

I have learned that the theory will not apply to every pond or lake. But if there is a well-defined ravine feeding into a body of water, it extends into the water. However, not all dry ravines travel a straight line. 

Some (like river beds) twist and turn. So the old depth finder still is useful in locating low spots on the bottom of standing waters.

I have always found it helpful in locating inundated ravines to observe the outlet of the body of water and line it up with the point where the ravine entered the impoundment. Then by spray-casting artificial lures (or live bait) to the imagined sweet spot, fish often will be located.

I also have found that this lay-of-the-land concept will work on totally unknown bodies of water while ice fishing.

It is, of course, important to realize that as a man-made impoundment ages the inundated ravines tend to level out as sediment from runoff settles. But even when this occurs the path of the ravine still will be lower than the surrounding bottom.