Rocky Mountains. IS 



and rose bays, gave the deep and narrow vallies the luxu- 

 riant verdure of spring. 



The Monongahela rises in Virginia, in the Laurel ridge, 

 and running northward receives in Pennsylvania the Yoho- 

 gany, whose sources are in the Alleghany mountain, oppo- 

 site those of the Potomac. This river, like most of those 

 descending westward from the Alleghany, has falls and ra- 

 pids at the points, where it insterects Laurel-hill, and some of 

 the smaller ranges. Along the fertile bottoms of the Alleg- 

 hany river, we begin to discover traces of those ancient works 

 so common in the lower parts of the Mississippi valley, the 

 only remaining vestiges of a people once numerous and pow- 

 erful, of whom time has destroyed every other record. 

 These colossal monuments, whatever may have been the 

 design of their erection, have long since out-lived the memo- 

 ry of those who raised them, and will remain for ages, affect- 

 ing witnesses of the instability of national, as well as indi- 

 vidual greatness ; and of the futility of those efforts, by which 

 man endeavors to attach his name and his memorial to the 

 most permanent and indestructible forms of inorganic mat- 

 ter. 



In the deep vallies west of the Alleghany, and even west 

 of the Laurel-ridge, the metalliferous limestone, which ap- 

 pears to be the substratum of this whole group of mountains, 

 is again laid bare. In this part of the range, we have not 

 observed those frequent alternations of clay-slate with this 

 limestone, which have been noticed by Mr. Eaton and 

 others in New England.* In its inclination, and in most 

 particulars of external character, it is remarkably similar to 

 the mountain limestone of Vermont, and the western coun- 

 ties of Massachusetts. Many portions of the interior of 

 the state of Pennsylvania, have a basis of this limestone. 

 When not overlaid by clay -slate, and particularly when not 

 in connexion with sandstone, the soils resting on the transi- 



* Geological Survey of Rensselaer conn ty. P. 11. 



