Tuesday, April 17, 2018

Rocky Mountain Locust: The Plague of the Pioneers

Photo by Darla Sue Dollman. I believe this was also a locust.

"No matter what they came to, they went right on. They were crawling up one side of the barn and down the other. Crawling West. They crawled straight into the creek, never stopped. They crawled into it and drowned till they clogged it up and the others crawled across on their backs. Molly...would they do something like that without knowing why? I tell you they were bound to go West. All the powers of Hell couldn't 've stopped them." He and Molly looked at each other for a long moment...Neither of them could say what they felt. The grasshoppers--crawling into the creek and drowning  'till the others crossed on their backs. Grasshoppers, going West--like the railroads, like the people, like cities and settled lands and law and government. Yet grasshoppers were as alien, as indifferent to human beings than human fate itself." 
--excerpt from Let the Hurricane Roar by Rose Wilder Lane, daughter of Laura Ingalls Wilder 

Locust in New Mexico arroyo. Photo by Darla Sue Dollman.

Here Come the Bugs!

It is spring, and my house is already alive with spiders and creepy crawly creatures. It sometimes seems that every year my home state of Colorado is plagued with some creature, such as moths, butterflies, or bees, but the one that has created a unique history of its own with its massive, nationwide invasions is the grasshoppers, or locust. Perhaps the most famous of these is the Rocky Mountain Locust with their massive attacks on American pioneers. 

The Rocky Mountain Locust and American Pioneers

Rocky Mountain Locust once swarmed in numbers unimaginable to modern farmers who use pesticides to protect their crops. According to the Fort Collins Museum Discovery Science Center, the 1874 swarm of Rocky Mountain Locust covered 198,000 square miles with an estimated 12.5 million insects. In the 1800s, farmers fought a seemingly endless battle with the locust, year after year, and many believed the locust would win. They gave up their dreams of farming and returned to their homes in the East.

Katie Bowell, Curator of Cultural Interpretation at the Fort Collins Museum & Discovery Science Center, "From July 20 to July 30 of 1874, a plague of locusts was recorded over the prairie that covered 198,000 square miles (approximately twice the size of my home state of Colorado) and contained at least 12.5 trillion individuals weighing approximately 27.5 million tons."

Laura Ingalls Wilder. Wilder and her daughter both wrote about the Rocky Mountain Locust plagues in their accounts of life on the American prairies. 

Laura Elizabeth Ingalls Wilder (1867-1957), Rose Wilder Lane's mother (quoted above) wrote the Little House series about her family life in Independence, Kansas, and also wrote about her family's experiences with the Rocky Mountain Locust in her books, including On the Banks of the Plum Creek, a story of her life on the American prairie.

Ingalls describes her impression of the locust as they moved toward her family farm: "The cloud was grasshoppers.Their bodies hid the sun and made darkness. Their thin, large wings gleamed and glittered. The rasping whirring of their wings filled the whole air and they hit the ground and the house with the noise of a hailstorm..."

Locust swarming on an outside wall in Kansas City. Photo taken in 1933. National Archives and Records Administration/Public Domain.

It is the 1870s and dreamers, pioneers, have suddenly become farmers responding to the 1862 Homestead Act. They packed their families and belongings and moved onto their 160 acres where they built sod homes, shanties, any kid of structure to meet the government residency requirements, but most of these homes were made of mud, sod houses that survived best against the blistering heat, harsh winds, and relentless snowstorms on the Western prairies and thankfully were the only type of home that locust could not eat.

They lived on their land for five years, planting, harvesting, waiting for the day when they could finally file the title to your property. Then suddenly one a quiet, sunny morning there appeared a black cloud above their homes moving closer, faster, descending on their crops, streams, barns, animals, dreams, like a giant beast destroying every little plant that grew from every little seed that these men, their wives and children dropped by hand into the soil just months before.

Rocky Mountain Locusts (titled Minnesota Locusts) of the 1870s. 
Jacoby's Art Gallery/Public Domain.

Those families who were familiar with locust tied the openings of their clothing--shirt sleeves, pant legs--with string so the locust wouldn't climb inside, then rushed to cover their wells with anything they could find. Some tried to burn part of their crops, hoping the smoke would discourage the locust. It did not.

The families hid inside their mud houses. The sound was horrendous--crunching, crawling, scratching. When the creatures could not find something to eat, they began to eat each other. When the ground was bare, they moved on. For some settlers in the West, the loss was too much and they returned back home to their families in the East.

A Distinct Species of Grasshopper

Rocky Mountain Locust. Annual report of the Agricultural Experiment Station of the University of Minnesota. (Biodiversity Heritage Library. Drawing by Julius Bien (1826-1909).

In 2010, when I first wrote this article, sources stated that all locusts are swarming grasshoppers in the Acrididae family. They become aggressive as their numbers grow and food sources become low.

However, it is now believed that the Rocky Mountain Locust, known as the M. spretus, is distinct. It once lived primarily in the Rocky Mountains, but spread into the prairies as its numbers grew, and continued to grow until clouds of locust filled the air for miles and miles. Between 1873 and 1877, locust swarms caused $200 million in crop damage in Colorado, Kansas, Minnesota, Missouri, and Nebraska. Imagine seeing a cloud of locust so large it covers the entire sky and turns day into night. As terrifying as a Bibilical plague.

Locust Plagues in History

Rocky Mountain Locust. Julius Bien (1826-1909) biography - Annual report of the Agricultural Experiment Station of the University of Minnesota. (11th July 1902-June 1903). Public Domain.

Author Jeffrey Lockwood also states in “The Devastating Rise and Mysterious Disappearance of the Insect that Shaped the American Frontier.”  that the largest swarm is believed to have happened in the American Midwest: "The 1875 swarm was estimated to contain several trillion locusts and probably weighed several million tons. That was the largest locust cloud in world history." 

According to an article in the New York Times, the 1875 swarm was equal to the size of "the combined area of Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont."

The Disappearance of the Rocky Mountain Locust

Twenty-seven years after the largest locust swarm in recorded U.S. history, the Rocky Mountain Locust mysteriously disappeared. The last sighting of a Rocking Mountain Locust was in Southern Canada in 1902. In spite of the size of the 1874 swarm less than 300 specimens of the insects remain. It is, however, still possible to find Rocky Mountain Locust carcasses frozen in glaciers.

In an ironic twist, it is widely believed that these same farmers who were relentlessly tortured by plagues of locust eventually brought about the locust's demise by exposing their larvae while plowing their fields.

According to Katie Boswell: "DNA testing from museum specimens of the Rocky Mountain locust suggests that M. spretus was a distinct, and now extinct, species and the days of the locust on the scale of 12.5 trillion individuals are gone. If you do still want to find Rocky Mountain locusts, the best place to look (other than in a museum) is in a glacier. Throughout the west there are glaciers that have preserved the frozen bodies of locusts that once flew over them."


  • Bennett, Chris. Western Farm Press. Accessed 2013. 
  • Bowell, Katie. The Rocky Mountain Locust. More to Explore. The Fort Collins Museum & Discovery Science Center. Accessed 2010.
  • Lane, Rose Wilder. Let the Hurricane Roar. Harper & Row Publishers. New York: 1933. 
  • Wilder, Laura Ingalls. On the Banks of Plum Creek. Harper: 1937. 
  • Yoon, Carol Kaesuk. "Looking Back at the Days of the Locust." The New York Times. Posted April 23, 2002. Accessed 2010.  

Christmas dinner for a family, from a series of photos documenting Gen. John J. Pershing's 1916 Punitive Expedition into Mexico. ...