There occur in Western states two species of hemlocks, both of which are found near Crater Lake. The Western Hemlock (Tsuga heterophyla) is of rare occurrence in lower altitudes of the Park. This is the tree so common in Williamette Valley and other lower regions outside the Park boundaries. The remaining species, the Mountain Hemlock, or as often called, the Black Hemlock (Tsuga mertensiana) is found only in the higher altitudes. It forms beautiful pure stands about the Rim of Crater Lake.

The two trees may be distinguished by the fact that the cones of the former are very small, rarely exceeding one inch in length, while the cones of the Mountain Hemlock are usually between 2 and 3 inches in length. Also the tips of the young branches of Western Hemlock are fuzzy, while those of the Mountain Hemlock usually are smooth. The cones of Western Hemlock usually are found all over the tree, while on the Mountain Hemlock they are found in the upper branches only. Lumber derived from the lower form is not extensively used while that of the mountain type is coming into more common use.

The firs most common in the Crater Lake region are the Noble Fir, (Abies nobilis) the Alpine Fir (A. lasiocarpa) and White Fir (A. concolor).

The largest of these is the Noble Fir. It is often found in pure stands and is the only one found on the Rim, altho not common there. It may be distinguished by the conspicuous reflexed bracts of the cone.

The Alpine Fir is common below the Rim especially near Park Headquarters. It is slender and spirelike in form altho scarcely ever exceeding 100 feet in height. The bark is thin, and the tree is often killed by extreme of temperature. The bracts are long and pointed but shorter than the scales of the cone.

The White Fir is found near the South Entrance. The branches are longer than any of the other firs.

The bracts of the cone are similar to the preceding but are abruptly sharp pointed, and can in this way be distinguished.