Sakakawea declared ‘ice free’ Wednesday morning

RIVERDALE – It was a call that came much later than many would have liked but sooner than expected. Lake Sakakawea was declared “ice free” at 8:45 a.m. Wednesday by the U.S. Army Corps of Engineers.

The observation is made yearly at the Garrison Dam Power Plant. A growing number of fishermen, boaters and others had been paying an increasing amount of attention to a very late ice pack that was rudely intruding on the recreation season. Guesses as to when the ice would finally leave the state’s largest reservoir varied widely and were revised daily.

Last weekend much of the upper end of Lake Sakakawea had open water but that was not the case on the lower end where a massive ice pack was shifting from shoreline to shoreline depending upon the prevailing wind. Such movement can be a nightmare for boaters who risk getting caught by shifting ice. Now, with ice no longer an issue, docks sitting alongside boat ramps can be moved into the water without the threat of being damaged by shifting ice.

Wednesday’s ice free declaration is one of the latest in the history of Lake Sakakawea. The May 9 date marks the fourth latest ice free date for the reservoir, surpassing May 8, 1956 for that dubious honor. The latest ice free declaration for Sakakawea was May 17, 1979.

This year’s unusually cold spring is credited with allowing ice to remain on Lake Sakakawea until such a late date. The reservoir endured 134 days of frozen water from December 17, 2017 to May 9, 2018. It’s another mark that will take its place as one of the longest such periods in the reservoir’s history, moving into sixth place all-time while surpassing the mark of 133 days frozen set in 2008-2009.

Latest ice free dates for Lake Sakakawea

May 17 – 1979

May 14 – 1970

May 13 – 2013

May 9 – 2018

May 8 – 1956

May 6 – 1996, 1997

May 5 – 1972, 1975

May 4 – 1965

May 3 – 1982

Most number of days frozen

165 – 1955-56

145 – 1978-79

138 – 2012-13

137 – 1956-57, 1958-59, 1961-62,1996-96, 1996-97

136 – 2000-01

134 – 1970-71, 2017-2018

133 – 2008-09

132 – 1969-70

130 – 1964-65, 1971-72