The term "hoofed locusts," is often incorrectly attributed to conservationist John Muir's 1876 letter to the Sacramento (Calif.) Record-Union titled "God’s First Temples: How Shall We Preserve Our Forests?"

The earliest mention I've found of "hoofed locusts," is in Muir's 1894 book, "The Mountains of California."

"But the arch destroyers are the shepherds, with their flocks of hoofed locusts, sweeping over the ground like a fire, and trampling down every rod that escapes the plow as completely as if the whole plain were a cottage garden-plot without a fence."

Ironically, one of Muir's first jobs in the Sierras was as a shepherd tending a flock of 2,000 sheep.

Photo by Nova Development Corp. Used under license.