In Search of the Source of the Wissahickon Creek

One of the most enduring legacies of the Presidency of Bill Clinton is his policy to make available GPS, the Global Positioning System, for civilian use. Early explorers may have trekked to the far corners of the world, but knowing their exact location is another matter. Recently, it was found that the Four Corners Monument marking the intersection of the boundaries of Arizona, Utah. Colorado, and New Mexico was 1807.14 ft. from the correct location, as found by GPS.

With the advent of GPS, many geographical mysteries can finally be solved. The National Geographic Society set out to determine the precise source of the Amazon River, which they found to be on Mt. Nevado Mismi in the Andes. The photograph is by Jialiang Gao.

It has only been in the last two decades that the source of the Mekong Rivers has been determined. The stream flows from the Lasagongma Glacier on the Tibetan Plateau in Qinghai, China.

While finding the source of the Wissahickon Creek may not require an expedition, the precise location of the creek bed is not always obvious as it can only be glimpsed intermittently. Also the problem arises as to what is creek and what is tributary. It is not so much the daunting distances of a mighty river, but the vagueness of the location of the creek. Geographer Andrew Johnston of the Smithsonian Institution offers (in National Geographic News): A source is defined as the most distant point (from the river mouth) in the drainage basin from which water runs year-around, or alternatively, the furthest point from which water could possibly flow into the ocean.