Abies grandis
White fir is very closely related to grand fir ("Abies grandis"), with subspecies "lowiana" being particularly similar to the interior variety of grand fir "A. grandis" var. "idahoensis", intergrading with it where they meet in the Cascades of central Oregon. To the south in Mexico, it is replaced by further close relatives, Durango fir ("A. durangensis") and Mexican fir ("A. mexicana").