The large deep lakes like Lake Bemidji, Cass Lake and Walker Bay of Leech Lake have become super-cooled by the persistent high winds that won’t let the lakes freeze, even though the water is more than cold enough to freeze.
The waves keep mixing the upper layer of the water column and won’t let the water stratify and freeze. This can drive the fish into deeper water than usual as the fish try to find the warmest water in the lake.
Wind can mix the water down past 30 feet deep, with the fish trying to get to the layer of water below the level where the water can be mixed by the waves.
The forecast for this week looks like there will finally be a night or two with both cold temperatures and light winds, so the deep lakes should begin freezing over at some point this week.
Once the lakes are frozen, anglers will need to remember which lakes have been frozen the longest, because the last lakes to freeze will have much less ice than the other lakes until well into the winter.
Meanwhile on the shallow lakes, there is between 4 to 6 inches of ice in most areas, with anglers tentatively beginning to venture out on the ice to begin the 2017/18 ice fishing season.
Upper Red Lake is always one of the first lakes to freeze, so it has been frozen longer than most of the rest of the lakes.
Upper Red Lake is very shallow, with most of the lake 12 feet deep or less. The big shallow lake is notorious for opening up big cracks and ice heaves when there are strong winds early in the season, especially when the winds blow from a west or northwest direction.
Anglers not only have to check the ice conditions when venturing out on the lakes, but they also have to monitor the wind and be sure the lake didn’t open up some big cracks between them and shore when they are leaving the lake.
The large lakes like Upper Red Lake, Winnibigoshish, Lake of the Woods, Leech Lake or Mille Lacs can break open in the wind, even when there is more than a foot of ice.
The ice heaves and pressure ridges usually form during strong winds along the windward portion of the lakes, which often affects the east and south shore of the lakes the most frequently.
Waves can form under the ice during strong winds. Anglers may notice the ice start to bob up and down as the wind builds during the day.
The waves under the ice will grow as they travel downwind. Once the waves hit the shoreline break or a shallow breakline on some downwind structure, the waves get pinched between the bottom of the lake and the bottom of the ice, which can put enough upward pressure on the ice to make it buckle and heave.
Anglers fishing on Upper Red Lake and other large lakes need to be careful on windy days, especially when accessing along the windward part of the lake. Just because the ice was good on the way out onto the lake doesn’t mean an ice heave didn’t form during the day between anglers and shore.
Anglers using snowmobiles or ATV’s to access the lakes need to drive slow enough when coming off the lakes to be sure they don’t overdrive their headlights and give themselves time to stop if something doesn’t look right when coming off the lake.
It is a long winter and there will be plenty of time for ice fishing. Anglers get anxious to get out on the lakes, but it is still very early in the season.
Please give the ice enough time to get thick enough to safely support anglers. Ice thicknesses will vary between lakes and even in different locations on the same lake early in the season.
Each lake has their own unique circumstances. Personally investigate any seams or cracks in the ice before crossing and stay safe this ice fishing season.