Tom Parkas, age 9, of Youngstown, Ohio, for his question:

How long, is the Mississippi River?

Up in Northern Minnesota, about 125 miles south of the Canadian border, there is a lovely lake amid the trees. It is Lake Itasca, the peaceful place where the mighty Mississippi is born. Right there, you can hop across the baby river with a single jump. From there it flows on and on toward the sea     and as it goes it grows. Other rivers run to join it     and the Mississippi gets to be a mile, then more than a mile wide. From its source, the great river flows about 2,348 miles and there at last it empties into the Gulf of Mexico.

The Mississippi and its great tributaries are an enormous system of rivers. To¬gether they drain water from 13 states and from two provinces in Canada. Geography experts tell us that the great river system actually begins with the mighty Missouri on the slopes of the western mountains. They say that the Missouri  Mississippi should be counted as one river. It measures about 3,872 miles which makes it the third longest river in the world.