LAKE CITY, Minn. – With ice encrusted on Lake Pepin, the Army Corps is setting the gear for its weekly borings to measure how deep. Borings will begin in February at scattered sites. The Corps uses the measurements to help project when commercial shipping on the Upper Mississippi can resume. The 22-mile lake, backed up from the Chippewa River isthmus, is usually the final barrier for barges to safely to navigate to the Twin Cities. Some years the ice is 30 niches thick.
