Hastings, MN (KROC AM News) - Most lakes in southern Minnesota are ice free for the first time this year. Robins and grackles are appearing in higher numbers, tulips are popping up and now there’s another sign of spring.

The Army Corps of Engineers is reporting the Motor Vessel Stephen L. Colby and its 12 barges locked through Lock and Dam 2, near Hastings, around 6 a.m. Thursday. The Colby was on its way to St Paul and had the honor of opening the 2017 shipping season on the Upper Mississippi River.

The Corps considers the first tow to arrive at the Hastings lock and dam as the unofficial start of the navigation season, because it means all of its locks are now accessible to commercial and recreational vessels.

The Corps says the earliest opening date is March 4th, which was achieved three times -  in 1983, 1984 and 2000. The average start date of the navigation season is March 22. Last year’s opening date was March 13.

It’s possible the season could have opened the earliest ever this year because the shipping channel was open last week. But maintenance work at a lock and dam in the Quad Cities area wasn’t completed until last weekend.

The Corps begins testing the thickness of Lake Pepin ice in February. This year, there was only one check because most of the ice was gone by March 1st.

For 24/7 news and sports check KROC AM and follow KROC-AM on Facebook.