208 THE ICE AGE m NORTH AMERICA. 



marked limits. Eastward it is continuous with the trough of 

 Lake Erie, and westward with the valley of the Wabash River. 

 At the north, or more properly the northwest, its slopes merge, 

 at a height of five hundred to six hundred feet (above Lake Erie), 

 with those of the valley of Lake Michigan ; and its southern 

 slopes, reaching a height of four hundred to five hundred feet, 

 pass into those of the Ohio valley. With these low sides and a 

 width of 125 miles, all its inclinations are exceedingly gentle, 

 and the title of plain can be applied to it with no less propri- 

 ety than that of valley. North of the Maumee the general de- 

 scent is to the southeast, and south of that river to the north- 

 east. With slight exceptions, the smaller streams follow and 

 indicate these slopes, but all the larger tributaries of the Mau- 

 mee, including the St. Joseph, St. Mary's, and Auglaize Eivers, 

 and Bean or Tiffin Creek, appear to be independent of them. 

 The St. Joseph, for example, flows to the southwest through a 

 country where every rivulet runs to the southeast. The entire 

 region drained by it lies on its right bank, while from its left 

 the drainage is toward Bean Creek, the divide between the two 

 streams being everywhere within three or four miles of the St. 

 Joseph. In like manner, the course of the St. Mary's is west 

 and north, and, while from its left bank the streamlets flow 

 northeast into it, from its right they flow northeast into the 

 Auglaize. These hydrographical peculiarities are so singular 

 and striking as to have excited some attention and curiosity 

 before the region was visited. Upon examination, there was 

 found a continuous ridge, following the eastern banks of these 

 rivers, and evidently determining their courses. Running 

 somewhat obliquely across the slopes of the country, it turned 

 aside all the small streams, and united them to form the St. 

 Joseph and St. Mary's. The height of this ridge is ordinarily 

 from twenty-five to fifty feet, and its width at base from four 

 to eight miles. Along the St. Joseph it is not distinguished 

 from the adjacent country by its superficial characters. In 

 common with that, it has a gently rolling surface, with a grav- 

 elly clay soil, supporting a heavy growth of varied timber. 

 Farther south, where it forms the north bank of the St. Mary's 

 River in Van Wert and Mercer counties, it is marked by such 

 peculiarities as to divide it very sharply from the adjoining 



