The Mountain Bluebird (Sialia currucoides) is a cavity-nesting species that breeds in a variety of open woodland habitats. Breeding habitats include groves of aspen and cottonwood (Populus spp.), pine woods including Pinyon Pine (Pinus edulis), and junipers (Juniperus spp.) (Bent 1949). The breeding territory usually includes a large area of open space where the nest is located and areas of trees or brush that provide cover nearby (Power 1966). Power (1966) concluded that the Mountain Bluebird had highly specialized nesting requirements and that the use of unusual sites was very rare.