A sure sign of spring is when the ice is gone from Lake Minnetonka, the metro area's largest lake.
That happened Sunday morning, when the Hennepin County Sheriff's Water Patrol took a spin on the lake and declared that boats can navigate through all of its channels and bays. The ice-out notice for 2015 is 19 days earlier than 2014, and nine days earlier than the median ice-out date of April 14.
The Water Patrol had help from the Freshwater Society, whose members monitored ice from shore and accompanied deputies on daily boat trips recently to check areas where ice remained.
Sheriff's deputies Jeremy Gunia and Shawn Eberle made the announcement Sunday morning with Kent Warden, Freshwater Society board member.
Ice-out records on Lake Minnetonka date back to 1855, and officials say they are a valuable if inexact method for revealing long-term trends.
The earliest ice-out date for Minnetonka was March 11, 1878, and the latest was May 5, 1887.
It's not an easy task to determine when the ice is gone, since Lake Minnetonka has 37 bays and is just over 14,500 acres in size. The definition of ice-out on the lake means that it's possible to boat through all the bays and channels without blockage, although some thin ice may remain in some areas.
An estimated 10,000 boats dock on the lake and 61,000 boats use its launches.