Male Western Bluebirds have blue throats while male Easterns have orange-red ones. Male Mountain Bluebirds lack any reddish coloration on their underparts.
Females are more difficult to separate.
Both Western and Mountain Bluebirds have gray throats and gray bellies while the Eastern Bluebird has a brownish throat and white belly. Open woodlands, clearings, farmlands, parks, orchards, gardens, fields, along roadsides on utility wires and fences. Numbers declined due to competition from starlings and house sparrows for nest sites. Making a comeback as people erect bluebird houses. Forest edge, burned or cutover woodland, open country with scattered trees.