Mixed in with the grassland, and usually at higher elevations, are four woodland and forest zones. First, at elevations below 1,900 m (6,200 ft) and at higher, drier elevations, the dominate tree species is the alligator juniper mixed with oak species and pinyon pine. Secondly, woodlands with pinyon pine as the most common species are found on steep slopes at elevations of 1,750 to 2,400 m (5,740 to 7,870 ft).