Dan DeVaney, U.S. Army Corps of Engineers, St. Paul District survey technician, measures the ice thickness at Lake Pepin, near Red Wing, Minnesota, Feb. 9. The lake is a part of the Upper Mississippi River. DeVaney is a part of a team that was collecting ice measurements to help the navigation industry determine when it is safe to break the ice and begin the 2021 navigation season.
Ice measurements are collected at Lake Pepin because the water flow is slower in this area and the ice is usually the thickest. Navigation officials typically waits until the ice is no more than 12 inches thick before sending barges north to break the ice en route to St. Paul, Minnesota.
