This year marks the 90th anniversary of the start of one of the greatest environmental catastrophes in American history: the Dust Bowl. Beginning in 1931, severe dust storms turned the southern Great Plains region into a wasteland. The storms snuffed out sunlight and dumped piles of dirt big enough to bury farms. 

The main cause of the disaster was poor farming techniques used by white settlers. In the early 20th century, farmers ripped up millions of acres of the area’s native prairie grass, which held the soil together, and planted wheat. Then a severe drought hit. Crops withered, and without the prairie grass, the soil was carried away by the wind. Soon, “black blizzards” became a frequent part of life there.

Millions of people—also reeling from the economic devastation of the Great Depression—left the region. Meanwhile, the federal government restored prairie grass and helped farmers develop new planting techniques to prevent soil erosion. Finally, in 1939, the rains came again and the land began to recover.