44 



The National Geographic Magazine 



Sand Dune Overwhelming a House at Manistee, Mich. 



This dune, originally stationary some distance away and covered with grass, was converted 

 into a shifting dune a few years ago by a party of townspeople celebrating a political victory 

 upon its brow with bonfires, thus destroying the grass. A blowout was formed, and, no repairs 

 being made, this gradually enlarged until the whole hill began to advance The dune advanced 

 eastward and soon threatened the city water- works and other property. This dune has now been 

 controlled by beach grass and brush. 



gan dunes are found at various places 

 along the south and east shore, but 

 none along the west shore. It is inter- 

 esting to note that the dunes in this 

 region are probably the largest and 

 highest to be found on the continent, 

 and are scarcely exceeded by any in 

 Europe. 



In nature, sand dunes are not formed 

 where the conditions will allow a cov- 

 ering of vegetation ; consequently they 

 are not found in warm regions or only 

 exceptionally, as the long vegetative 

 season allows opportunity for a cover- 

 ing to become established ; but in 

 northern regions, where vegetation lies 

 dormant for a considerable portion of 

 the year, the severe winter storms may 

 prevent such a covering from forming. 



The chief areas of shifting dunes to 

 be found along the Atlantic coast are 



on Cape Cod, in the vicinity of Province- 

 town; southern New Jersey, near Avalon 

 and Stone Harbor; Cape Henlopen,near 

 Tewes, Delaware ; Cape Henry, Vir- 

 ginia, and less extensive, though quite 

 troublesome, dunes at Currituck, North 

 Carolina ; Isle of Palms, near Charles- 

 ton, South Carolina ; and Tybee Island, 

 near Savannah, Georgia. 



Sand dunes occur at various places 

 along the Pacific coast, as Ventura, 

 Monterey, and Mendocino counties, Cali- 

 fornia, and the coast of Oregon. The 

 latter are minimized by the moist climate. 

 Extensive and exceedingly troublesome 

 dunes are found along the Columbia 

 River in Oregon and Washington from 

 The Dalles to Riparia. The sand is 

 brought down during the floods and 

 blown about during the long dry sum- 

 mers. Here the conditions as to rain- 



