VALLES CALDERA NATIONAL PRESERVE, N.M. — The lush grass in northern New Mexico provides a strong lure for drought-stricken ranchers looking for a way to feed their animals. But grazing in the mountains brings a risk of bovine high altitude disease, a potentially fatal illness that costs the beef industry some $60 million a year.

As many as 2 million cattle graze on public and private land at high altitudes every summer, but with thousands developing the disease each year, ranchers take a chance when they send their animals into the hills. Read more…