The breeding habitat of the Mountain Chickadee (Parus gambeli) throughout its range is coniferous forest at middle to high elevations (Grinnell and Miller 1944, Bent 1946, Behle 1956, Dixon 1961, Laudenslayer and Balda 1976, Garrett and Dunn 1981, Unitt 1984). This species is most typically associated with coniferous forests but can also occur in mixed stands of conifers and hardwoods, including Black Oak (Quercus kelloggii), Quaking Aspen (Populus tremuloides), and cottonwoods (Populus spp.) (Linsdale 1938, Grinnell and Miller 1944). At their lower elevational limit and in the mountain ranges of the Great Basin and eastern Mojave Desert, Mountain Chickadees nest in pinyon–juniper woodland (van Rossem 1936, Linsdale 1938, Johnson 1965, Cardiff and Remsen 1981, Garrett and Dunn 1981). Pinyon Pine (Pinus monophylla, P. edulis), Utah Juniper (Juniperus osteosperma), and White Fir (Abies concolor) are the dominant conifers of these ranges.