Amy Schutte March 21 2018. More than 72,000 wild horses roam through the Western states on land that experts say can no longer sustain their basic needs. These horse herds double in size every four or five years at a growth rate of approximately 20 percent a year and have reached a capacity that far succeeds what the 1971 Wild Free-Roaming Horses and Burros Act and the Bureau of Land Management (BLM) dubs the appropriate management level (AML) (full Article)