More than 400 native plant species live in the park. There are three life zones in the park based on elevation: the lowest areas of the park are dominated by dwarf forests of pinyon pine and juniper with manzanita, serviceberry, and antelope bitterbrush in between. Aspen, cottonwood, water birch, and willow grow along streams. Ponderosa pine forests cover the mid-elevations with blue spruce and Douglas fir in water-rich areas and manzanita and bitterbrush as underbrush. Douglas fir and white fir, along with aspen and Engelmann spruce, make up the forests on the Paunsaugunt Plateau. The harshest areas have limber pine and ancient Great Basin bristlecone pine, some more than 1,600 years old, holding on.