They are ALL natural. If they were salt they would be a Sea.
As suggested by the name, the Great Lakes are all lakes - bodies of fresh water. Seas are bodies of salt water.
none of the great lakes are man made all of them were made from nature
Mississippi river great lakes great salt lakes Colorado river Okeechobee river Columbia river
Irrigation of the Great Lakes could result in Salinization. It would be turned from freshwater to salt water. All of the salt would stay while the water would be drawn out leaving mostly all salt found behind. It could end up in the lakes shrinking.
yes, there aarae salt mines under all the great lakes
Salt lakes exist around the world in all continents.
You mean " Are All Lakes Fresh Water?" : No they are not all Fresh water: Most Notably : The Great Salt Lake is Saltier then the Ocean ; Lake Peigneur , Saltwater lakes take up 55% of the total area of Chinese lakes, of which the most famous is the Qinghai Lake.
Lake Erie is one of the Great Lakes which are all Fresh Water the Great Lakes are the largest fresh water lakes in the world.
No, all LAKES are freshwater. OCEANS are saltwater. Lake Michigan is a freshwater lake, but the answer above is false. See, for example, http://en.wikipedia.org/wiki/Great_Salt_Lake or http://en.wikipedia.org/wiki/Lake
No. Lake Michigan, like all of the Great Lakes, is fresh water only.
The way the question is worded, the only feasible answer is that all lakes worldwide with the exception of Lakes Superior, Michigan, Huron, Erie, Ontario are NOT one of the Great Lakes.
Lakes Huron, Ontario, Michigan, Erie, and Superior are all freshwater lakes.