The first up-bound tow of the 2013 navigation season crushed through more than 12 to 16 inches of ice at Lake Pepin on the Mississippi River early in the morning on Monday, April 8.

The Motor Vessel Roberta Tabor, a tow owned by American River Transportation Company in St. Louis, locked through the Corps' Lock and Dam 2 in Hastings, Minn., shortly after 8 p.m., en route to St. Paul, Minn. The motor vessel was pushing 12 barges.

Lake Pepin is the last part of the river to break up, because the river is wider and subsequently the current is slower there than it is at other reaches of the river. If a tow can make it through Lake Pepin, it can make it all the way to St. Paul.

The average opening date of the navigation season for the last 30 years has been March 20. Last year, the Motor Vessel Deana Ann was the first up-bound tow to pass through Lake Pepin. She arrived March 17.

The Corps considers the first tow to arrive at Lock and Dam 2 as the unofficial start of the navigation season because it means all of its locks are available to commercial and recreational vessels. The earliest date for an up-bound tow to reach Lock and Dam 2 was March 4, in 1983, 1984 and 2000. The latest arrival date unrelated to flooding was April 4, 2008. Historic flooding in 2001 delayed the arrival of the first tow until May 11.