MARYLAND WEATHER SERVII E ;j.j 



physiography of the Mountain Zone is in the sequential stage 

 throughout, and even in the narrowest and steepest valleys rock out- 

 crops are rare and of limited extent. The valley between Big 

 Savage and Meadow Mountains is drained by the Savage River, 

 which flows to the Potomac through the narrow valley which sepa- 

 rates Big Savage and Backbone Mountains. The upper drainage 

 basin of the Savage has the most rugged and precipitous topography 

 of any portion of Maryland, many slopes being at the grade of 

 1200 ft. to the mile and exceptional ones 2500 ft. to the mile. To 

 the west of Meadow and Great Backbone Mountains the Mountain 

 Zone is drained by the Castleman and Youghiogheny rivers, which 

 are in the drainage basin of the Mississippi. 



Peculiar to the Mountain Zone are the Swamps which are found 

 along the upper waters of many streams draining narrow mountain 

 valleys in which the longitudinal slope is not. great. There is such a 

 swamp two miles south of Finzel in Garrett County, and another at 

 the head of Pine Swamp Run about four miles north-west of Barton, 

 and more extensive ones occur at Cranesville and Thayerville. In 

 the central plateau of Garrett County there are considerable areas of 

 alluvial bottom land which have been built up by the deposition of 

 eroded material in these swamps. The bottom lands are known 

 locally as "glades." 



Shore-Line Topography. — Constant changes are taking place in 

 the outline of the coast of the Ocean and Chesapeake Bay which are 

 due to the destructive action of waves and tidal currents in wearing 

 away the shore-line and the constructive action of the filling of in- 

 lets and marshes by the depositing of the eroded material. The 

 shore-line topography of Chesapeake Bay is in a sequential stage, 

 having undergone considerable changes since the Talbot uplift, and 

 being still far from a condition approaching stabilization. The 

 destructive phase of change in shore-line topography is of little 

 interest in its relation to vegetation, as it merely destroys Upland 

 forest or Marsh. The constructive phases, however, result ulti- 

 mately in the presenting of new habitats for occupation by plants, in 

 which the physical conditions are usually of a marked character, so 

 as to be hostile to the generality of Upland species. Rapid changes 



