affected by the Dust Bowl between 1935 and 1938, originally prepared by the
Soil Conservation Service. The most severely affected counties during this period are colored . , in 1935. The Dust Bowl area lies principally west of the
100th meridian on the
High Plains, characterized by plains that vary from rolling in the north to flat in the
Llano Estacado. Elevation ranges from in the east to at the base of the
Rocky Mountains. The area is
semiarid, receiving less than of rain annually; this rainfall supports the
shortgrass prairie biome originally present in the area. The region is also prone to extended drought, alternating with unusual wetness of equivalent duration. During wet years, the rich soil provides bountiful agricultural output, but crops fail during dry years. The region is also subject to high winds. During early European and American exploration of the
Great Plains, this region was thought unsuitable for European-style agriculture; explorers called it the
Great American Desert. The lack of surface water and timber made the region less attractive than other areas for
pioneer settlement and agriculture. The federal government encouraged settlement and development of the Plains for agriculture via the
Homestead Act of 1862, offering settlers "
quarter section" plots. With the end of the
Civil War in 1865 and the completion of the
first transcontinental railroad in 1869, waves of new migrants and immigrants reached the Great Plains and greatly increased the acreage under cultivation. An unusually wet period in the Great Plains
mistakenly led settlers and the federal government to believe that "
rain follows the plow" (a popular phrase among real estate promoters) and that the region's climate had permanently changed. While initial agricultural endeavors were primarily
cattle ranching, the harsh winters' adverse effect on the cattle, beginning in 1886, a short drought in 1890, and general
overgrazing, led many landowners to increase the amount of land under cultivation. Recognizing the challenge of cultivating marginal arid land, the U.S. government expanded on the offered under the Homestead Act, granting to homesteaders in western Nebraska under the
Kinkaid Act (1904) and elsewhere in the Great Plains under the
Enlarged Homestead Act of 1909. Waves of European settlers arrived in the plains at the beginning of the 20th century. A return of unusually wet weather seemingly confirmed a previously held opinion that the "formerly" semiarid area could support large-scale agriculture. At the same time, technological improvements such as mechanized plowing and mechanized harvesting made it possible to operate larger properties without increasing labor costs. With insufficient understanding of the ecology of the plains, farmers had conducted extensive
deep plowing of the
Great Plains' virgin
topsoil during the previous decade; this displaced the native, deep-rooted
grasses that normally trapped soil and moisture even during periods of
drought and high winds. The rapid mechanization of farm equipment, especially small gasoline tractors, and widespread use of the
combine harvester contributed to farmers' decisions to convert arid grassland (much of which received no more than of precipitation per year) to cultivated cropland. During the drought of the 1930s, the unanchored soil turned to
dust, which prevailing winds blew away in huge clouds that sometimes blackened the sky. These choking billows of dustnamed "black blizzards" or "black rollers"traveled cross-country, reaching as far as the
East Coast and striking such cities as
New York City and
Washington, D.C. On the plains, they often reduced visibility to or less.
Associated Press reporter Robert E. Geiger happened to be in
Boise City, Oklahoma, to witness the "
Black Sunday" black blizzards of April 14, 1935; Edward Stanley, the Kansas City news editor of the Associated Press, coined the term "Dust Bowl" while rewriting Geiger's news story. The term "the Dust Bowl" originally referred to the geographical area affected by the dust, but today it usually refers to the event itself (the term "Dirty Thirties" is also sometimes used). The drought and erosion of the Dust Bowl affected that centered on the
Texas Panhandle and
Oklahoma Panhandle and touched adjacent sections of New Mexico, Colorado, and Kansas. The Dust Bowl forced tens of thousands of poverty-stricken families, who were unable to pay mortgages or grow crops, to abandon their farms, and losses reached $25 million per day by 1936 (equivalent to $ million in ). Many of these families, often called "
Okies" because many of them came from Oklahoma, migrated to
California and other states to find that the
Great Depression had rendered economic conditions there little better than those they had left. The combined effects of
World War I and the disruption of the
Russian Revolution, which decreased the supply of wheat and other commodity crops, increased agricultural prices; this demand encouraged farmers to dramatically increase cultivation. For example, in the
Llano Estacado of
eastern New Mexico and northwestern
Texas, the area of farmland doubled between 1900 and 1920, then tripled between 1925 and 1930. The agricultural methods farmers favored during this period created the conditions for large-scale
erosion under certain environmental conditions. The widespread conversion of the land by deep plowing and other soil preparation methods to enable agriculture eliminated the native grasses that held the soil in place and helped retain moisture during dry periods. Furthermore,
cotton farmers left fields bare during the winter, when winds in the High Plains are highest, and
burned the
stubble as a means to control weeds before planting, thereby depriving the soil of organic nutrients and surface vegetation. ==Drought and dust storms==