Mapping the Sand Hills

    H.T.U. Smith (1965)  was the first to classify and map the dunes of the Nebraska Sand Hills. He studied low altitude aerial photography and topographic maps.  He did not have the advantage of satellite or high altitude imagery.

    He postulated that the dunes were formed in a series of three episodes beginning 8,000 to 10,000 years ago during the early stages of the Wisconsinan glacial period.  He surmised that the first dunes were formed under prevailing north winds. These were the largest dunes that ran generally east to west - transverse to the prevailing winds.  

    According to Smith the dunes were stabilized with vegetation until another drought  led to the second episode. The dunes deposited in the second episode were aligned longitudinally with the prevailing winds.  These were smaller than those of the first episode.  The longest of which were about 2 miles. Those of the third episode were much smaller and represent a sort of random rearrangement of the the sand deposited earlier.

    A more detailed description of Smith's work can be found in the document, Dunes on the Plains -The Sand Hills Region of Nebraska by Charles Keech & Ray Bentall. 


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