WINONA, Minn. (AP) - This year's shipping season is underway on the Mississippi River, an earlier than average start buoyed by warmer temperatures and reduced snowfall.

The first tow to arrive at Lock and Dam 2 near Hastings is the unofficial start of the navigation season because it means all of the locks are accessible to commercial and recreational boats. The Robert Wagonblast locked through on Sunday, pushing 12 barges en route to St. Paul.

The average start date for shipping season is March 22.