GREEN RIVER -- Another wild horse roundup has been approved for Wyoming rangelands as federal officials continue to work to bring wild horse numbers down to acceptable levels.

Bureau of Land Management managers issued a Record of Decision on Monday approving the wild horse gathering operations from the remote Fifteenmile Herd Management Area near Worland.

The Fifteenmile HMA is located approximately 30 miles northwest of Worland, within Washakie, Big Horn and Park counties in north central Wyoming. The area includes rolling hills, rugged canyons and badlands, and a portion of the Bobcat Draw Wilderness Area.

Plans call for capturing the wild horses from the approximately 83,000-acre Fifteenmile HMA as part of a population-control strategy that aims to manage the area in a range from 70 to 160 mature horses.

Officials said the operations involve capturing about 280 wild horses, returning about 70 mature animals to the HMA, and removing the remainder of the horses.

An environmental assessment released by the BLM in September 2008 said the appropriate management level for wild horses in the HMA is from 70 to 160 mature horses.

Horses were last gathered in the HMA in 2004.

The document said the sex distribution of the 70 horses returned to the HMA would be approximately 60 percent males to 40 percent females, to help slow the growth rate of the herd.

Federal biologists counted 232 animals during an aerial census of wild horse populations in February 2008.

Officials said the census revealed about 79 of the horses counted were living outside of the HMA boundary.

The gathering operations will include helicopter drive trapping, which utilizes a helicopter and on-the-ground wranglers to herd wild horses into a temporary trap.

The BLM has removed 906 wild horses from the Fifteenmile HMA during five previous roundups dating back to 1984, according to the EA.

Too many horses

In Wyoming, there are about 4,500 wild horses scattered across 16 herd management areas in the state, although most of the animals live on public lands and some private lands in southwest Wyoming.

The BLM has a statewide objective of from 2,700 to 3,700 wild horses, according to agency officials.

Federal officials say wild horses have no natural predators, and with an annual reproduction rate of between

15 and 20 percent, the excess animals must be periodically removed from public rangelands to achieve population objectives.

Wild horses that are captured during roundups in Wyoming are taken to the BLM's holding facilities in Rock Springs, where they are offered up for adoption.

The agency also has agreements with the Wyoming Honor Farm in Riverton, a state correctional facility, where wild horses are trained by residents, and with the Mantle Ranch near Wheatland, where wild horses are also gentled and trained.

In 2003, after wild horse populations in Wyoming soared upwards of 7,000 animals, the state and the BLM signed a "consent decree" dictating that the agency meet the state's wild horse objective number with roundups over the next few years.

Federal wranglers have also gathered wild horses this year in roundups in the North Lander Complex in central Wyoming and the Red Desert Complex in southwest Wyoming.

Contact southwest Wyoming bureau reporter Jeff Gearino can be reached at 307-875-5359 or gearino@tribcsp.com