Thirty-five years ago, Stephen Trimble wrote a book called The Sagebrush Ocean: A Natural History of the Great Basin. Today, he says, a book about the same place might be titled The Cheatgrass Ocean: An Unnatural History of the Great Basin, as the highly flammable weed expands across the deserts of Nevada and Utah. Add a second encroachment of piñon and juniper trees, and sagebrush is in danger of disappearing. The dilemma is how to hold onto and add to the sagebrush that's left.