Dear Answer Man, in years past I've seen airboats cruising around on the ice about this time of year. Is that safe? — R.R.
For private citizens, you'd have to say no, but the Army Corps of Engineers uses an airboat to take its annual ice measurements on the lake, and in fact those may happen as early as today.
A crew operating from Fountain City, on the cheesy side of the river, will be measuring the thickness of the ice to make predictions on when the shipping season on the Upper Mississippi will begin. Using GPS, they measure the thickness of the ice at several points and record the general condition of the ice, which at this point must be getting at least a bit soupy. Wait until Thursday, when temps hit 50!
The data is posted on the Corps of Engineers website , which also includes historical data on ice-out along the Mississippi.
Last year's first tow to reach St. Paul was the Motor Vessel Bernard G, a tow based in Bettendorf, Iowa, on April 11. Over the past 10 years, the average opening date has been about March 10, but don't look for it before March 15 this year, because of construction at a lock and dam downriver.
