VALLEJO, Calif. (KGO) -- "Stop the round-up!"So chanted a crowd hundreds of miles from the nearest wild mustangs and directly in front of the US Forest Service Southwest Regional Headquarters.That agency has begun rounding up 1,000 mustangs in the Modoc National Forest of Northern California -- a region it describes as overpopulated and stressed."They are over their carrying capacity. You can put it that way," said John Exline, who manages ecology for the Forest Service."These are American icons," said Suzanne Roy of the Wild Horse Campaign. "They will be bought by kill buyers and trucked to Canada for slaughter. " Now, her group has filed suit in federal court to guarantee the Forest Service does not sell any rounded up horses, especially the old ones, for food if no one adopts them.The Forest Service says that would be a last resort.If the wild mustang movement has a so-called poster person, it would be Ellie Phipps Price, who has 240 of the animals -- most at a sanctuary, and others, like her first mustang, named Dunston, in Sonoma County. Wild mustangs are national treasures, she says. "They are sure-footed, great-minded, connect with people."And protected, she notes. So when the Department of Forestry conducts a round-up, she wants it done differently."I agree there needs to be more management. Humane management. Birth control. It's never been used."The federal government would not sell one of those unwanted horses for at least a year.Next move belongs to the courts.