Crotalus willardi obscurus
Barker, D.G. 1991. An investigation of the natural history of the New Mexico ridgenose rattlesnake, Crotalus willardi obscurus. 100 p.
Holycross, A.T. 1996. Recommendations for limiting impacts of prescribed burns on Crotalus willardi obscurus. Unpubl. letter to USFWS. Arizona State University, Department of Zoology, Tempe, AZ. p. 5.
Holycross, A.T. 1995. Status of the Animas Mountains Population of Crotalus willardi obscurus. Unpubl. Preliminary Report of Activities Conducted Under Professional Service Contract No. 95-516-28 for the New Mexico Department of Game and Fish (NMDGF). Ari
Holycross, A. T. 1999. A Map of Potential Core Habitat for Crotalus willardi obscurus on Coronado National Forest Lands in Peloncillo Mountains: A Report to Malpai Borderlands Group. Biology Department, Arizona State University, Tempe, AZ, p. 164.
Smith, L.J., Holycross, A.T., Painter, C.W., Douglas, M.F. 2001. Montane Rattlesnakes and Prescribed Fire. The Southwestern Naturalist. 46(1): 54-61