Thirteen studs, 12 mares and three yearlings were captured on Thursday during the ongoing helicopter roundup at the Reveille Horse Management Area in Nevada.

A total of 151 wild horses have been captured since the roundup began on Jan. 30, according to the Bureau of Land Management. One wild horse has been euthanized.

BLM plans to capture 140-160 wild horses from the HMA and surrounding area, which is located about 50 miles east of Tonopah, Nevada.

About 80 wild horses are to be permanently removed from the range and put up for adoption, according to the BLM, while 60 to 80 will be released. All released mares are to treated with fertility control vaccine.

A portion of the Reveille HMA is subject to a 1987 court order and 2001 and 2001 Interior Board of Land Appeals orders requiring BLM to conduct an annual population count. If the count exceeds BLM’s Appropriate Management Level (set at 138 wild horses in 2001), the agency has 120 days to begin a roundup to removed “excess” wild horses, beginning with wild horses outside of the HMA’s boundaries.

The Tonopah Resource Management Plan allows BLM to reduce the wild horse population to a level that will accommodate up to three years of population growth before again reaching Appropriate Management Level.

The goal for the upcoming roundup: reduce the population to 91 wild horses. The current population is estimated at 173 wild horses, based on an inventory flight in February 2016 and an annual estimated growth rate of 15 to 20%, according to BLM.