Forest zones east of the Cascades are generally defined as being Rocky Mountain forest types. The Fremont is on the boundary of the floristic Great Basin and reflects this with the presence of typical Great Basin flora, including sagebrush (Artemisia sp.) and bitterbrush (Purshia sp.). The dominant conifer species is ponderosa pine (Pinus ponderosa). Current ecological structures are the result of 100 years of fire suppression.