passage of the wild horse annie act did not alleviate the concerns of free-roaming horse advocates, who continued to lobby for federal rather than state control over the disposition of free-roaming horses. since most horses in the desert regions were recently descended from ranchers' horses, ownership of the free-roaming herds was contentious, and ranchers continued to use airplanes to gather them. johnston continued her campaign and in 1971, the 92nd united states congress unanimously passed the wild and free-roaming horses and burros act of 1971. it was signed into law by the then president richard nixon on december 15, 1971. this act prohibited capture, injury, or disturbance of free-roaming horses and burros.