LAKE CITY, Minn. – The Army Corp, which controls Upper Mississippi navigation, found the ice pack on Lake Pepin as thick as 20 inches. This is what’s called blue ice – solid with no air bubbles. Twenty inches is typical for mid-February. In places the ice in the Mississippi lake’s 20-mile navigation channel was as thin as six inches. The measurements are performed weekly to guide the Corps on when the lake can be opened safely for commercial barge traffic for the season.
Auguring below ice. Army Corps surveyor Brandon Olson bores into the ice on Lake Pepin for data to forecast the navigational outlook. The thickness is important because Lake Pepin’s ice is the last major barrier for barges being pushed upriver to the head of navigation at St. Paul. Image: Melanie Peterson
