TWO NATURAL BRIDGES. 



79 



This bridge is so surrounded by trees that it is impossible to get a good 

 view of the arch, but the figures of its dimensions will give some idea of 

 its size. 



The greatest inside length of the span is 67}/ 2 feet, its height 33 feet, 

 and the thickness of the arch in the center is 18 feet. The width of the 

 arch at this point is 35 feet, while it is 135 feet from end to end. The 

 bridge, which at both ends has a width of 50 feet, is separated from the 

 main bluff by a distance of 19 feet. The Morgan Spring sandstone which 

 composes the bridge is a coarse, yellowish, white sandstone, and does not 

 weather easily. Occasionally one will find a few small, white, quartz 



FIG. 3. Gcoch Creek natural bridge. (W. A. N.) 



pebbles. The rocks are mostly massive and thick bedded, and have a dip 

 of about two degrees toward the mountain, which is to the northwest. 

 The Morgan Springs sandstone is from 100 to 200 feet thick and forms 

 a well defined escarpment along most of the eastern face of Walden Ridge. 

 In the face of the bluff back of the arch of the bridge is a small basin- 

 like spring about four feet from the foot of the bluff, which forms a nat- 

 ural drinking basin. At the time the locality was visited, which was dur- 

 ing a very dry period, the flow was so weak that the overflow was just 

 sufficient to wet the surface of the bluff below the spring. Only during 

 the wet seasons does any water flow through the arch, and this comes 



