Federal wildlife managers are expanding habitat for bison at the Rocky Mountain Arsenal National Wildlife Refuge in Commerce City.
The Denver Post reports U.S. Fish and Wildlife officials plan to double the size of the refuge habitat to nearly 6,400 fenced acres by the end of 2016. The herd of 89 bison is expected to grow by up to 120 bison.
Land managers have been using different practices to promote grass growth to sustain a larger herd at the refuge, a site that was once damaged by toxic chemicals.
Projects are also in the works to introduce plains sharp-tailed grouse, lesser prairie chickens and pronghorn antelope at the site. Biologists recently released 30 endangered black-footed ferrets.
Officials have set a long-term goal of growing the refuge to 12,000 acres.