Geography of Ohio 229 



static water, and as a result deposit their loads. The products of 

 stream erosion, thus deposited near the mouth of the river, build 

 a ''delta." Since streams vary with the seasons, in their velocity 

 and volume, their loads are sometimes carried farther out into 

 the lake before being deposited. If the volume and velocity were 

 constant the year round, the river would shortly clog its own 

 mouth and build a dam. Even under normal river conditions, 

 deltas eventually attain such size that they rise above the lake 

 level, and the stream takes one or several courses across it. Towns 

 situated at the mouths of lake rivers are forced to make annual 

 appropriations for dredging the stream, so as to keep the harbor 

 open. Delta deposits gather rapidly, even at the mouths of old 

 streams. Lake currents shift delta material somewhat, but never 

 to the extent of distributing it all. About the borders of deltas, 

 these currents form spits and barriers, which become a further 

 menace to navigation. 



The shores of islands have the same history as any other shore 

 lines. If the island, through cliff development, furnishes an ample 

 supply of material, lake currents will deposit spits, oriented with 

 the prevailing wind. Sometimes barrier beaches are constructed, 

 not infrequently, through the development of a bar the island may 

 become land-tied. About all islands, we find the same catalogue 

 of shore phenomena as are associated with the shore lines proper. 



When the prevailing beach material is sand, dunes develop. 

 The wind carries the sand in front of it, and, if the shore line lies 

 athwart the wind, the dunes travel inland. Extensive dune areas 

 are found in the northern part of the state, many miles south of 

 the shore of Lake Erie. The material of these dunes represents the 

 wave work of the high level lakes; they are especially abundant 

 south of Sandusky, a typical area existing in the vicinity of 

 Bellevue. 



Geographic influences. Shore lines have elicited a variety of 

 responses in man's activities. Long before anyone appreciated 

 their significance, or even the former existence of ice front lakes, 

 man used the old beaches for highways, frequently calling them 

 ''ridge roads." A high percentage in the linear extension of the 

 beaches of the three ice-front lakes now carry highways. Even 

 some of the spits, built into former bays, are used for roadbeds. 

 In some localities, the three beaches are quite parallel for consider- 

 able distances; here the farms run from beach to beach, or the 



