Great Plains farmers migrated to California in the 1930s because drought conditions and erosion-producing agricultural methods created the decade-long phenomenon known as the Dust Bowl. Because they were unable to survive in such an arid, hostile environment, many farmers left the region and journeyed to California to look for work.
In the 1920s, favorable weather, plentiful rainfall and new technology such as gasoline-powered tractors produced bumper crops of wheat on the Great Plains of Texas, Oklahoma, Kansas, New Mexico and Colorado. However, farmers gave little consideration to the prairie grass that secured the topsoil, which they decimated by deep plowing. When the first of several droughts came in the early 1930s, strong winds blew the topsoil off the land. Up to 100 million acres of land were affected by the disaster. The area became oppressed by immense dust storms known as black blizzards. Crops failed, cattle died, dwellings became suffused with dust, and people became sick and died from a malady called dust pneumonia.
Storms decimated many houses. Others lost their homes and farms due to bank foreclosures. Hundreds of thousands of former Great Plains farmers, known as Okies or Arkies, sought migrant work in California to avoid starvation. This caused conflict with long-term residents and taxed local relief agencies. In 1935, President Franklin Roosevelt signed a bill authorizing the planting of over 200 million trees in the Great Plains region to impede the wind and stave off soil erosion.