The Saint Mary's River and the St. Joesph River converge in Fort Wayne to form the Maumee River. The area's most important geographical feature is the short overland distance between the Three Rivers system, which eventually flows to the Atlantic, and the Wabash system, which eventually flows to the Gulf of Mexico. This became the portage, or carrying place, where travelers could transport cargoes from one system to the next. This natural crossroads attracted Native Americans for thousands of years, then European explorers and traders, and later American pioneer settlers who developed the area as a transportation and communications center. At the Treaty of Greenville in 1795, Chief Little Turtle of the Miami Nation called it "that glorious gate…through which all the words of our chiefs had to pass from north to south and from east to west." At the end of the last Ice Age, 12.000 years ago, the retreating glacier of the Wisconsin Lobe left a unique continental divide that deflected the waters of the St. Joseph and the St. Mary's rivers east into glacial Lake Maumee and the waters of the great Wabash River system west toward the Mississippi River. In time, Lake Maumee became the center of the Great Black Swamp, which extended throughout northwestern Ohio to Lake Erie; the Maumee River drained this ancient swamp and for centuries was the only highway through it. It is not known who named the rivers, but they were probably given their European names by an early Catholic priest who passed through the area. The first clergyman known to have passed through was the Reverend Joseph Pierre de Bonnecamps, a professor of hydrography at the Jesuit College of Quebec, who visited the rivers' confluence in 1749 on a scientific expedition.