1. Agee, J.K., 1993. Fire Ecology of Pacific Northwest Forests. Island Press, Washington, DC, p. 493.
2. Arno, S. 1979. Forest regions of Montana. USDA Research Paper INT-218.
3. The northwestern U.S. during deglaciation;Barnosky,1987
4. Modeling paleoclimates;Bartlein,2003