I. C. White — Bowlders at high altitudes. 377 



ting the few stranded bowlders to be shed into the valleys by 

 subsequent erosion. 



All who are familiar with the region about Pittsburgh, and as 

 far down the Ohio as Bellevue, cannot have failed to observe 

 the immense deposits of transported bowlder trash that have 

 accumulated about the junction of the Allegheny and Monon- 

 gahela rivers. The beautiful valley of East Liberty and Home 

 wood owes its origin to the submergence of this region to such 

 a depth that a branch of the Monongahela once extended across 

 the divide near Homewood, and connected with the Allegheny 

 several miles above the present junction. The extreme eleva- 

 tion of the great bowlder heaps around Pittsburgh is about 300 

 feet above water level (1,000 feet above tide). At Sewickley 

 the great deposit ends about 160 feet above the river; near the 

 mouth of Beaver it is only 125 above; and still farther down 

 the Ohio the top limit of the deposit declines to 100, and often 

 to not more than 80 feet above low water. 



In the vicinity of Sewickley, during the past year, I dis- 

 covered transported bowlders extending up to nearly 600 feet 

 above the Ohio, or more accurately 1,250 feet above tide. It 

 is true the same observation had previously been made along 

 the Ohio near Sisterville, but this being then the only known 

 instance of water-worn bowlders at such a great elevation, and 

 only a few of them being found, it was considered probable that 

 the Indians had carried them up from the valley for some pur- 

 pose. They are not abundant at this great elevation in the 

 vicinity of Bellevue and Sewickley, but the farmers report that 

 they plough them up occasionally in every field for about one 

 mile back from the river. None was seen of a diameter greater 

 than 6 inches. From the fact that these few scattering bowlders 

 are confined to the river valley, I still think it very probable 

 that they were carried to these high levels by the Indians. 

 Granitic bowlders of small size have also recently been found 

 near Washington, Pa., at the head of Chartiers Creek, which 

 empties into the Ohio river a short distance below the mouth of 

 the Allegheny. I have seen only a few of these, but Mr. A. J. 

 Montgomery, on whose farm they occur, reports that a large 

 number of them were found in digging a ditch for the natural 

 gas main, a short distance outside of the borough. The eleva- 

 tion of the Chartiers Yalley railroad depot is 1,030 feet above 

 tide, and the granitic bowlders picked up near Mr. Montgom- 

 ery's were about 20 feet higher. This locality is so far (30 

 miles) from the Ohio Valley that we cannot, with much degree 

 of plausibility, ascribe the presence of the bowlders to Indian 

 transportation, and especially the regular bed of them which 

 Mr. Montgomery saw in the Pipe Line ditch. As the Chartiers 

 Yalley is almost a direct (southward) continuation of the Alle- 



