Ultimate Outdoor Adventures - Identifying River Structure

Identifying River Structure

By: Kurt Schirado

Each year river systems are some of the first bodies of water to break free from their frozen covering and each year these ever changing water ways have new and unfamiliar navigational paths and fishing structure. Learning to navigate a river channel each spring can be some what intimidating. With a little know how and patience you too can learn how to "read the signs" and make it a pleasure instead of a chore.

I grew up fishing the Missouri River near Bismarck, North Dakota as a child and continue to make it my favorite body of water to pursue migrating spring and fall walleyes. I've learned a few things over the years, mostly from trial and error and by spending numerous days on the water with friends and family. Most rivers systems are similar in many ways, so once you learn how to "read the water" on one fast flowing waterway, you can apply your knowledge to almost any river, lake or reservoir.

Each spring as the ice breaks free from the main river channel many eager and ambitious anglers approach the water with high hopes. It seems that each season I hear more and more people complaining about low water conditions, floating logs, sandbars, deadheads (submerged logs stuck in the river's bottom) and hard to navigate water ways. Any experienced "river rat" knows that each year a river system changes due to its strong current, water and wind erosion and floating ice jams so each spring your first day on the water should be set aside for navigation. Take your time, learn the river channel and look for unfamiliar debris that has appeared since last season. Things like deadheads and relocating sandbars and water ways are the main structural differences to identify.

In certain areas of a river system the main channel never seems to change but on the other hand, other large portions of a river will always shift from year to year. Navigating through these areas can be tricky but taking your time and learning to "read the water" can make all the difference in being a successful river angler or being stuck on a sandbar for the next two hours. I think we've all been there before and nobody wants to be there again so let's learn a few things to help make your next trip to the river more enjoyable.

In the previous paragraph I talk about "reading the water," what this means is learning to identify structural changes under the water by seeing slight changes in the waters surface. Any color change, swirl or ripple on the surface usually means there is a structural change below. If any of these signs are identified slow down and investigate by using your electronics. These spots can be dangerous due to submerged logs, rocks and or sandbars; or they might be a sure sign to a new fishing hotspot.

Once I've navigated down stream a few miles I then take my time and look for new fishing holes on the way back to the ramp area. I choose to look for shallow water hotspots while traveling up stream do to the fact that if I happen to get hung up on a sandbar, I can always float off it down stream using the current to my benefit. I'm always looking for shallow water spots up and over a submerged shelf or ridge.

After ice out, spring walleyes are usually located in deeper holes. These areas are identified by large swirling water pockets, outside bends in the main river or they may be located on the down river side of a sandbar. Fish these areas early on and then watch for the walleyes to move to shallow slack water areas with tapering sand or rock ledges or shallow under water troughs (saddles). Once again, these areas usually taper off the tail end of a slightly submerged or above water sandbar.

A long under water shelf or ledge is usually identified by a color change in the waters surface that stretches a long distance. The surface color will appear lighter or darker than the adjacent water and it tends to stretch the length of the sandbar as long as it's only slightly under the waters surface. Another way to describe it is that the surface water stretching the length of the underwater sandbar tends to look as if there's an oil slick flowing down stream. These under water shelves are great areas to troll shallow running cranks, horizontal jig upstream or drift down stream pitching light jigs up on the ledge itself. I like to position my boat in 8-10 feet of water and pitch a 3/16 ounce jig tipped with a minnow up on to the ridge and slowly hop it back to the boat, letting it tick bottom with every bounce. I prefer to make my first pass upstream trolling cranks or horizontal jigging and then drifting down current pitching jigs. This allows me to apply two different techniques on the same structure letting the fish dictate what they prefer. If no fish are boated on the first pass up and back, I relocate to the next hotspot.

Other areas to key on while searching mainstream river channels are inside turns on shorelines or sandbars. These areas might be long and subtle or may be a drastic switchback. It's easy to see these hotspots with the naked eye but be cautious of the water depth. It tends to be a bit shallow in these areas so navigate with caution. These long stretches of shoreline and or sand are key areas to troll shallow running cranks such as #11 or #13 floating Rapalas, Little Rippers or Shad Raps.

I prefer somewhat low water conditions just for the fact that it's easier to identify structure. Sandbars are visually present with obvious slack water fishing holes tucked closely behind. If water levels tend to be high, it takes more time to locate submerged sandbars and therefore making it harder to find fish holding structure. I can usually pick a good fishing hole by just seeing it or what I referred to earlier as "reading the water". I always check my suspicions by slowly running my boat over the area to confirm the depth is suitable (6-10 feet with a shallow taper is ideal).

"Reading the water" is something that takes practice but its well worth your time and effort. Pay attention to the smallest of details when exploring any new body of water and especially an ever changing river system. It makes navigation much easier and less intimidating plus it can save on your lower unit and prop. That alone is worth your effort and a few bucks.

Editors Note: Kurt also mentioned that a calm sunny day works best for "reading the water" or seeing water changes and separation on the surface. He also said that good sonar/GPS units, such as the ones manufactured by Lowrance Electronics, Inc., are also a key to his success while fishing and navigating rivers.

Photos from top to bottom: 1) The first photo shows water disturbance created by a submerged tree; this tree was approximately 12 inches below the surface. The photo was taken from the down current side of the tree. 2) The second photo is a deep hole or eddy. It happens to be on the outside bend of the river channel which has eroded part of the cut bank creating a deep hole. You can visually notice these areas because of the slight swirling of the surface current and they can typically be good spots during the pre-spawn. 3) The third photo shows a distinct underwater sandbar. The choppy surface water is the slack current and the calm surface water is the top of the sandbar. You may also notice the pockets along the edge of the sandbar. Oftentimes walleyes will be found up against the bar waiting to ambush their prey as it comes over the top of the bar. Pitching small jigs tipped with minnows along the bar, especially into the pockets, can be very productive. Trolling crankbaits while paralleling the bar is also an effective way to catch a lot of river eyes. 4) The bottom photo shows what many river rats refer to as a traditional current break. It is where the swift river current meets and parallels the more slack water which is usually found behind a sanbar or other structure that is slowing the river current. Notice how it looks similar to an oil slick.