By MEAD GRUVER

Associated Press

CHEYENNE, Wyo. (AP) -- The federal government began another wild horse roundup Tuesday in the same area of southwest Wyoming where a ranching association is trying through legal means to get even more wild horses removed from the sagebrush country.

A U.S. Bureau of Land Management contractor will round up about 1,400 of the estimated 1,640 wild horses northeast of Rock Springs. Some 200 horses will be released back on the range, including mares treated with a birth control drug that stays effective for almost two years.

Of the remaining 1,200 horses, the younger ones will be put up for adoption and older ones sent to pastures in Kansas, Oklahoma and the Dakotas, BLM spokeswoman Serena Baker said.

The roundup has been going smoothly, though officials were watching to see if snow and wind would ground a helicopter used to herd the animals. "Those helicopters can't fly in much more than 20 mph wind, which as you can imagine is pretty commonplace in Wyoming in the winter," Baker said.

The latest roundup isn't as controversial as one northwest of Rock Springs last summer that initially called for gelding stallions and spaying mares. Even so, a horse advocate said the BLM ought to explore alternatives to rounding up so many horses. The BLM could reduce cattle and sheep grazing so that the range would have more forage to sustain more wild horses, suggested Suzanne Roy with the horse campaign.

"Despite the promises of reform by this agency, we're just seeing more of the same, which is mass roundup and removal of horses," Roy said Tuesday.

The last roundup in the area northeast of Rock Springs was in August 2007. This August, the BLM rounded up nearly 700 wild horses in the Eden area northwest of Rock Springs.

The Eden roundup implemented a new BLM policy that calls for removing fewer wild horses from western ranges -- about 7,600 a year instead of 10,000 -- and more reliance on fertility control methods to limit the wild horse population.

Both recent roundups north of Rock Springs occurred in a vast area of interspersed private and BLM land where members of the Rock Springs Grazing Association run cattle. A lawsuit filed by the association in U.S. District Court in Cheyenne last summer said the BLM has not abided by a 30-year-old agreement to limit horse numbers.

The association's lawsuit seeks to remove all wild horses from its grazing allotment.

The American Wild Horse Preservation Campaign sued over the August roundup because of the plans to spay and geld, which the group said would have wiped out the herd. A judge dismissed the case after the BLM decided to administer a birth control drug to mares instead.

Now the campaign and two other groups, the International Society for the Protection of Mustangs and Burros and the Cloud Foundation, have filed to intervene in the Rock Springs Grazing Association lawsuit on the BLM's side. A judge had not yet ruled on the motion.

A spokeswoman at the BLM's state headquarters office in Cheyenne declined to comment because the matter is under litigation.

Elsewhere in Wyoming, a roundup southeast of Lander earlier this month collected about 580 wild horses, of which about 230 were returned to the range. A roundup north of Rawlins next month will target about 400 horses.

Copyright 2011 The Associated Press.