If you visit the doctor, he has a way to tell if you are sick or not. He might take your temperature, check your ears or look into your throat. Scientists are checking into the health of sagebrush rangelands in the Great Basin, and the prognosis is not good. In areas of Utah, Nevada, Idaho, California, Oregon and Washington, rangelands are under threat from invasive plants.

Since the settlement of the American West, pinyon and juniper trees have expanded across Utah’s Great Basin, crowding out native bunchgrasses and shrubs. Landscapes that were once high-desert prairies are now thick with thirsty trees.