This guidebook describes The Island Research Natural Area, an 84-ha (208-ac) tract established to represent examples of the western juniper/big sagebrush/bluebunch wheatgrass (Juniperus occidentalis/Artemisia tridentata/Pseudoroegneria spicata), and the western juniper/big sagebrush-antelope bitterbrush/bluebunch wheatgrass (Juniperus occidentalis/Artemisia tridentata-Purshia tridentata/Pseudoroegneria spicata) plant associations.