Rocky Mountain Locust Swarm

In 1895, a swarm of Rocky Mountain locusts measuring 1,800 miles long and 110 miles wide, blocked out the sun for 5 days. Thirty years later the locust was extinct. Between outbreaks, the locust hid out in the river valleys of Wyoming and Montana, the same river valleys that settlers had discovered were best suited for farming. By converting these valleys into farms, diverting streams for irrigation, allowing cattle and sheep to graze in riparian areas, and eliminating beavers and their troublesome dams, the pioneers unknowingly wiped out locust sanctuaries.