Lake Thompson, South Dakota: "Big Lake on the Prairie"
By Matt Walsh

De Smet, South Dakota was the setting for Laura Ingalls Wilder book "The Little Town on the Prairie" and was home to Laura Ingalls who moved to De Smet when she was twelve back in 1879. Located four miles east and six miles south of "The Little Town On the Prairie" is "The Big Lake On the Prairie" Lake Thompson a sprawling prairie lake covering 16,236 acres of water with depths to 22 feet. Did Laura Ingalls ever get the chance to flip and pitch jigs for shallow water walleyes on Lake Thompson? Hard o say, the area went through eighty year cycles of filling up with water and then drying up until the late 1980's when consecutive years of heavy snow runoff and rain formed what is now Lake Thompson.

Back Bays, Weeds, and Walleyes

If you have never caught a walleye in less than four feet of water and experienced the fight of these tackle-busting brutes than June on Lake Thompson would be well worth the trip. Although there are many shallow flats on the main lake the water in the back bays warms earlier than the main lake and the emerging weeds and spawning carp are walleye magnets. Walleyes move shallow to take advantage of this emerging life and cover. This pattern will last until the bays become weed choked or the food supply diminished usually until the end of June.

On the very northeast side of Lake Thompson is a large bay part of that is called Schaffer's Slough. This shallow bay provides many options with varying structure. Trees, weeds, rocks, submerged roads, and underwater stock dams just to name a few. Note: Depending on water levels navigation can be hazardous move with caution until acquainted with the area. Maps are available featuring 163 GPS way points from Mike's Maps (605.352.0407).

Schaffer's Slough and other bays have expansive weed flats. To cover these areas quickly, put out planer boards with shallow running crankbaits and set the line so the crankbaits just tick the top of the weeds. In most cases the water will only be three to six feet so very little line is required. A pattern will emerge to where the concentrations of walleyes are located. To avoid spooking the walleyes with the motor, stop, and cast crankbaits or jigs in the area. When casting crankbaits in the weeds Fireline (10 pound test) is recommended. When the lure comes into contact with the weeds a swift jerk of the rod tip will not only keep the lure free of debris this action will many times will a produce a strike.

Cold Front Adjustment

The worst case scenario for this back bay weed pattern is cold fronts or extreme wind. The walleyes don't leave the area but they will bury themselves deep in the weeds. In this situation a change in tactics is in order. First, find an area out of the brunt of the wind. Then, slowly drift a split shot rig or anchor and cast slip bobbers with leeches. This slower more methodical approach will increase your odds in this situation.

If the weed pattern slows don't overlook the other structure in the bays. Trees, underwater roadbeds, neck down areas, and stock dams are all good options. Some times just moving a few feet deeper is the last piece of the puzzle.

The Main Lake

As summer wears on the main lake shallow bite heats up with distinct weed lines formed adjacent to deeper water. Position the boat just on the outside of the weed line, again, casting crankbaits or jigs into the weeds. In this situation where the boat is clear of weeds take out a dead rod and place it in a rod holder. Rig the dead rod with a bottom bouncer, spinner and nightcrawler moving just fast enough to turn the spinner. The effectiveness of this method is covering two areas at once the inside the weed line as well as the weed line itself. On many occasions the dead rod will out produce every other technique even though the bait is directly underneath the boat in 5-6 feet of water!

Weeds are not the only cover walleyes are attracted to on Lake Thompson. A unique characteristic of the lake is the amount of trees popping out of the water especially in the southeast corner of the lake. These trees attract walleyes don't overlook this potentially big fish pattern. Pitch jigs or cast crankbaits right up into the trees or work the edges and bring plenty of tackle. This can be frustrating fishing with all the snags but can also pay off with a real brute.

On the main lake during the summer months pay close attention to water clarity and wind direction. Lake Thompson walleyes are programmed to feed on wind blown shorelines or where the water clarity is diminished.

Planning a Trip?

The Lake Thompson Recreation Area is located on the northeast shore and features a double lane boat ramp, dock, fish cleaning station, and public restroom facilities. Adjacent to the boat ramp is a state campground with electrical hook ups, showers, camping cabins, and a swim beach. Reservations may be made on line at www.campsd.com or call 800.710.CAMP. Conveniently located just before the campground entrance is the North Shore Bar and Grill. If a motel meets your needs try the Cottage Inn (800.848.0215) or the Super 8 (605.854.9388) in De Smet. If coming from the east or Interstate 29 stop by Mac's Bait in Lake Preston located on highway 14 for the latest information and excellent selection of bait.

Less than a days drive away Lake Thompson is approximately 90 miles from Sioux Falls, 275 miles from Omaha, 260 miles from Minneapolis, and if coming from the west 54 miles north of Interstate 90.

Lake Thompson limit on walleyes is four (one over 20" and three with no lower limit) the possession limit is eight. Fishing with two rods per person is permitted.

Besides walleyes Lake Thompson offers has a large population of northern pike and jumbo perch, with an occasional crappie or smallmouth bass. However, now is the time to take advantage of the feeding frenzy taking place in the shallows by the walleye population. If only Laura Ingalls Wilder could have experienced these marauding packs of walleyes there might have been another book in her series called "The Big Lake on the Prairie."

Matt Walsh guides on Lake Thompson and the Missouri River he is owner/operator of The Walleye Wrangler Guide Service (www.walleyewrangler.com).