It’s not like we need more proof that this has been one tough winter for most of America. Still, here's dramatic new evidence: The five Great Lakes are virtually frozen over. Ice covers nearly all of Erie, Huron, and Superior, while about 80 percent of Lake Michigan and Lake Ontario are solidly encased by sheets of ice. The figure was around 90 percent two weeks ago. "The amount of ice cover is not unprecedented," says Canadian environmental scientist John Nevin of Windsor, Ontario, "but it's as much as we've seen probably since the 1970s."

Even though that’s a sign of the Midwest’s and Northeast’s deep freeze, there are upsides. Commercial and recreational boaters will benefit from higher water levels because ice reduces evaporation. A lower amount of moisture escaping into the atmosphere should mean fewer clouds and less snowfall, although that surely hasn't been the case in some areas. And the safe-to-walk-on lakes brought increased tourism in parts of northern Michigan, Wisconsin and Minnesota, where visitors could reach scenic offshore caves and ice formations that usually are out of bounds this season.

The most extensive ice cover on record came in 1979, when the Great Lakes overall were 95-percent covered. To prepare for the return of cargo freighters to the lakes late next month, nine U.S. Coast Guard icebreakers and two from Canada will try to clear shipping channels in the weeks ahead. And lastly, here’s a memory hint to help you recall all five lakes' names" Use HOMES as a reminder of their first letters.

Lakes expert says: "You suffer through this hard winter, all this cold and ice, but there is a silver lining. It's really positive for the lakes." – John Nevin, International Joint Commission in Windsor, Ontario

Professor says: "We haven't seen many winters like this that are cold from beginning to end. It has been an extraordinary winter." – Jeff Andresen, associate professor of geography at Michigan State

Coast Guard says: "If we continue on the track we are on, we're going to have more ice than we have icebreakers to deal with it." -- Mark Gill, U.S. Coast Guard in Sault Ste. Marie, Mich.