The Fourth River

When people think of Pittsburgh, they usually think of the city of three rivers. The Allegheny and the Monongahela Rivers meet at the Point and form the mighty Ohio River. At the very junction of the river, in the historic and geographic birthplace of the Ohio Valley, a fountain was built to symbolize the meeting of the waters and the rivers' part in the settlement and economic growth of America's heartland. The fountain has a jet capable of rising 150 feet, and is the trademark of Pittsburgh. It is also the largest fountain in America.

Unknown to most, the water in the fountain of Point State Park comes not from one of the visible “Three Rivers” but from a little known and unnamed fourth river of Pittsburgh. The fountain source is a subterranean river about 54 feet below the surface at “The Point.” An underground glacial stream, it is considered a never-ending source of water for the fountain. Called the Wisconsin Glacial Flow by geologists, it was formed by the Wisconsin ice sheet that covered much of the Northern United States during the Ice Age of 70,000 years ago.

Today it flows south from beneath the Great Lakes and under Western Pennsylvania; at Pittsburgh's Point it flows due south, contrary to the Three Rivers. The water is fresh and pure, 55 degrees, with no bacteriological count, and is actually the source of drinking water for some of downtown Pittsburgh. Pittsburgh's "underground river" is called an "aquifer"—but it differs from other aquifers in that most of them are irregular and widespread, and do not follow a channel—making it more like a true river.

For more information, please see The Point: The Fountain at The Point