The Diamond Mountain HMA is located east and north of the town of Eureka, Nevada. The Diamond Mountain, Diamond Hills South and Diamond Hills North Herd Management Areas (HMAs) are all part of the Diamond Mountain Range. The horses move freely between the HMAs. The only reason that there are three separate HMAs is because the Diamond Mountains are administered by three different Field Offices. The Diamond Mountains are the highest mountain range in the Shoshone Eureka Planning Area and wild horses can be found at elevations to 10,000 feet.
The mountain range is approximately 60 miles long and 12 miles wide. The Complex containing all of the three HMAs covers over 236,000 acres. Newark Valley lies east of the mountain range and Diamond Valley is to the west at 5,700 feet in elevation. During periods of heavy snowfall, wild horses will move off the mountain into the valleys. As a matter of interest, the northern end of Diamond Valley contains a large alkali (salt) flat, which is common in many valley bottoms in Nevada.
During a capture of wild horses, conducted from August 1 through August 23, 1997, 1,397 horses were captured within and outside the boundaries of the HMAs. Of the total captured 1,177 of the horses were transported to Palomino Valley Center north of Sparks, Nevada for preparation into the adoption program. The remainder, ages 10 to 28 years old, were released back inside the HMA boundaries.
The most recent gather was completed in 2004, in conjunction with the other two HMAs within the Complex. The gather involved the capture of 643 wild horses followed by the release of 116 wild horses back to the range. Fertility control was also implemented on 86 of the released mares.
The primary colors of the horses captured from within the Diamond, Diamond Hills North & Diamond Hills South included bays, sorrels, and browns. Other colors included palomino, buckskin, chestnut, grey, variations of roan, and pinto/paint.
The current estimated population on the Battle Mountain side of the mountain range is 129 horses. The Appropriate Management Level (AML) is 151.