LAKE CITY, Minn. – Ice remained at 22 inches on parts of Lake Pepin in the latest weekly measurement by the Army Corps of Engineers. At its thickest, the ice pack was 11 inches of solid blue ice and 11 of bubble-infused white ice. At seven of the Corps measuring points there was open water. Elsewhere, the Mississippi river’s navigation channel was clear of ice. And so too the lower reaches of the Black, Chippewa, LaCrosse, Trempealeau and Zumbro rivers – although not the backwaters.
Bore points. The Army Corps has 25 points to check Lake Pepin ice to help calculate when it’s safe to open the lake to towboats and barges. The maps shows the typical mid-winter ice pack. The darker the color, the thicker the ice. The Mississippi River navigation channel through the 22-mile lake is the mid-lake line.