Trees and shrubs are the main forms of plant cover on ultramafic soils of the southern exposure of the Rattlesnake Creek terrane (RCT) in the Klamath Mountains. A detail soil survey of the ultramafic soils revealed differences in the extent of green conifer tree canopy cover related to soil depth and altitude on the cool and cold soils. The green conifers were Jeffrey Pine (Pinus jeffreyi Balf.), Incense Cedar (Calocedrus decurrens [Torr.] Florin), Douglas-Fir (Pseudotsuga menziesii [Mirb.] Franco), and Sugar Pine (Pinus lambertiana Douglas) on cold soils. Warm soils, at less than about 1000 m altitude (asl) east of Tedoc Mountain to <800 m asl west of Hyampom, lack conifers other than Gray Pine (Pinus sabiniana Douglas). Green conifer cover areas increase from 0% on the warm soils to >40% on cold soils of the Hyampom-Tedoc Mountain area. Farther west in the RCT, the smaller Brannon Mountain-Hoopa area had more landscape and plant community disturbance and less altitude-conifer canopy cover relationships. The conifer tree canopy cover-soil depth relationship in the Hyampom-Tedoc Mountain area is more pronounced than on cool and cold soils in most other parts of the Klamath Mountains. The differences are greater between very shallow and shallow soils than between shallow and moderately deep soils. The differences are expected to be even less pronounced between moderately deep and deep soils, but there were too few deep soils to test this hypothesis effectively. Gray Pine was the only conifer on the warm ultramafic soils and it prevailed in chamise chaparral from below Tedoc Mountain toward the Yolla Bolly Junction at the northern end of the Coast Ranges fault.