Field photo of several greeri found under rocks, two obviously in a shed cycle, near Otinapa, DGO, August 2008. Photo by C. Rodriguez.

Field photo of a greeri from north of Coyotes (Banderas de Aguila), at approx. 8000 ft/2438 m. Found by Ed Cassano, James R. McCranie, and Louis Porras in early September, 1974. Photo by Ed Cassano, courtesy of Louis Porras.

Young adult female, Rancho Santa Barbara stock.

Young adult male greeri, Rancho Santa Barbara stock.

Young adult female, Rancho Santa Barbara stock.

Captive-produced adult male, Rancho Santa Barbara stock.

Captive-produced adult male, Rancho Santa Barbara stock.

Young adult greeri, f1 from wild-caught Rancho Santa Barbara, DGO, parents. Sibling to snakes in next two images.

Juvenile greeri can be seen in the vertical crevice just beneath the stick, photographed in situ. Copyright 2007 by Ronald Savage.

Photo depicting habitat of specimen in preceding photo. Copyright 2007 by Ronald Savage.

Juvenile greeri in hand following extraction from crevice. Copyright 2007 Ronald Savage.

Adult greeri (CM 118916) collected from Mimbres Canyon, Durango. Photo by G. T. Salmon.

Juvenile greeri collected by Henry Wallace in Durango. Photo courtesy of G. T. Salmon.

Adult greeri from near Cd Durango, Henry Wallace collection. Photo courtesy of G. T. Salmon.

Type specimen of Lampropeltis greeri (MSU 190), photographed in the field at Rancho Santa Barbara, Durango, by Robert G. Webb in 1958. Photo courtesy of G. T. Salmon.

Head shot of adult male greeri shown in previous photo, illustrating head markings typical of this population.

Adult male greeri from Rancho Santa Barbara, Durango.

Adult female greeri from Rancho Santa Barbara, Durango.

Approaching an outcrop, Tim Burkhardt and Troy Hibbitts observed this lone greeri basking at the opening of a deep crevice. This is typical thermoregulatory behavior for montane Lampropeltis, which will position a coil at the edge of a crevice. Especially following a meal, the snake is likely to position the food lump in the warmest spot to accelerate digestion. Vic. of Otinapa, Durango, elev. 7816 ft (2382 m). Photo © 2007 Troy D. Hibbitts.

Tim Burkhardt and Troy Hibbitts discovered a pair of greeri sharing crevice space in August 2007 near Otinapa, Durango, elev. 7816 ft (2382 m). The snake on the right, a young female, was in a shed cycle; she was later extracted for photos and then returned to her crevice. Photo © 2007 Troy D. Hibbitts.

Small adult female in shed cycle, extracted from her crevice for photos then released. This snake will undoubtedly look much lighter and more colorful once she sheds. Vic. of Otinapa, Durango, elev. 7816 ft (2382 m). Photo © 2007 Troy D. Hibbitts.

Small adult female in shed cycle, extracted from her crevice for photos then released. This snake will undoubtedly look much lighter and more colorful once she sheds. Vic. of Otinapa, Durango, elev. 7816 ft (2382 m). Photo © 2007 Troy D. Hibbitts.

Greeri being returned to her home crevice following photos. Vic. of Otinapa, Durango, elev. 7816 ft (2382 m). Photo © 2007 Troy D. Hibbitts.

Captive-produced young adult male, the result of line breeding for reduced black pigment, descended from Rancho Santa Barbara animals.

Photograph of the juvenile greeri, taken in captivity several months after collection. This was the only specimen observed during a period of intense searching for this species. Its discovery (ca. 70 air km NNW of Ciudad Durango) extends the range of greeri northward and brings this species to within ca. 80 airline km of the mountain-dwelling population of L. alterna reported by Ingrasci et al. (2008). Refer to Savage and Hansen (2009) for details. Photo copyright 2007 Matthew Vaughan.

Field photo from Rancho Santa Barbara, Durango. Photo courtesy of Joseph Forks.

Field photo from Rancho Santa Barbara, illustrating the characteristic head marking of greeri. Photo courtesy of Joseph Forks.

This unusually-patterned greeri was found by Joe Forks and Alan Kardon at Rancho Santa Barbara, Durango, in August 2005. Photo courtesy of Joseph Forks.

This closeup view of the head reveals a distribution of pigment not often seen in greeri. Photo courtesy of Joseph Forks.

Field photo of an adult female, Mesa Montoro, Aguascalientes.

Field photo of an adult female, Mesa Montoro, Aguascalientes.

Field photo of large adult male, Sierra de Laurel, Jalisco. Snakes from this populations are provisionally referred to greeri pending further study.

Closeup of the head of a juvenile greeri from the Sierra de Laurel. Field photo.

This juvenile from the Sierra de Laurel exhibits a ringed pattern not previously seen in greeri. Field photo.

Head shot of adult, Sierra de Laurel, Jalisco. Field photo.

Adult greeri from the Sierra de Laurel, Jalisco. Of five snakes we have seen from this range, 3 display this look, which is nearly bicolored considering the near absence of orange in the dark saddles. Field photo.

Field photo of a greeri from north of Coyotes (Banderas de Aguila), at approx. 8000 ft/2438 m. Found by Ed Cassano, James R. McCranie, and Louis Porras in early September, 1974. Photo by Ed Cassano, courtesy of Louis Porras.

Field photo of an adult greeri from the vicinity of Bandera del Aguila, Durango. Photo courtesy of Louis Porras.

Field photo of a greeri from north of Coyotes (Banderas de Aguila), at approx. 8000 ft/2438 m. Found by Ed Cassano, James R. McCranie, and Louis Porras in early September, 1974. Photo by Ed Cassano, courtesy of Louis Porras.

Field photo of a greeri from north of Coyotes (Banderas de Aguila), at approx. 8000 ft/2438 m. Found by Ed Cassano, James R. McCranie, and Louis Porras in early September, 1974. Photo by Ed Cassano, courtesy of Louis Porras.

Field photo of an adult greeri from the vicinity of Bandera del Aguila, Durango. Photo courtesy of Louis Porras.

Young adult greeri, f1 from wild-caught parents (Rancho Santa Barbara, DGO).

Young adult greeri, f1 from wild-caught parents (Rancho Santa Barbara, DGO), showing much darker green ground color than two siblings depicted in previous images.

Field photo of an adult greeri found near Otinapa, Durango, 2005. Photo courtesy of C. Grünwald.

Closeup of the head of an adult greeri from near Otinapa, DGO, displaying head markings typical of Durango populations. Photo courtesy of C. Grünwald.

Young greeri found at Rancho Santa Barbara, DGO, September 2005. Photo by C. Rodriguez.

Field photo of a nearly bicolored greeri at Rancho Santa Barbara, DGO, September 2005. Photo by C. Rodriguez.

Young adult female greeri, captive-bred F1 from Rancho Santa Barbara, Durango parents.

Young adult male greeri, captive-bred F1 from Rancho Santa Barbara, Durango parents.

Young adult male greeri, captive-bred F1 from Rancho Santa Barbara, Durango parents.

Adult greeri field collected by Chris Rodriguez and Chris Grünwald at Mesa de Nayar, Nayarit, August 2010. This is the first greeri (or any member of the L. mexicana complex) found in Nayarit. Although this individual does not look much like "typical" greeri found farther north in Durango, the other two snakes from the same locality (also shown in this gallery) have that standard greeri appearance. See Hansen et al. (2011) for details. Photo courtesy of C. Rodriguez.

Juvenile greeri from Mesa de Nayar, Nayarit, field collected in August 2010 by Chris Rodriguez and Chris Grünwald. Photo courtesy of C. Rodriguez.

Subadult greeri field collected at Mesa de Nayar, Nayarit, in August 2010 by Chris Rodriguez and Chris Grünwald. Photo courtesy of C. Rodriguez.

Young adult female, het for low-black trait but displaying typical wild phenotype.

This juvenile from the Sierra de Laurel on the Jalisco/Aguascalientes border exhibits a ringed pattern not previously seen in greeri. Compare this to the other two specimens from the same locality. Field photo.

Adult greeri from southwestern Zacatecas (vic. La Cienega, Mpo. Atolinga, elev. 2328 m), the first greeri reported from this vast state. This snake was found by Ivan Ahumada-Carrillo and colleagues in September 2008 (see Ahumada-Carrillo et al. 2011). Photo courtesy of Ivan Ahumada-Carrillo.

Closeup of adult greeri from southwestern Zacatecas. Photo courtesy of Ivan Ahumada-Carrillo.

Adult greeri from Cerro de la Virgen, just south of Cd Zacatecas, ZAC, Mexico. The snake was found by Luis Almaraz in June 2011. A view of the collection site may be seen in the Habitat gallery. Photo courtesy of Luis Almaraz.

Adult greeri from Sierra Huichola, Jalisco. Photo courtesy of Iván Trinidad Ahumada Carrillo.

Head closeup of the adult greeri shown in preceding photo. Sierra de Huichola, Jalisco. Photo courtesy of Iván Trinidad Ahumada Carrillo.

Adult greeri, Sierra Huichola, Jalisco. Photo courtesy of Iván Trinidad Ahumada Carrillo.

DOR greeri, showing an unusual, greatly reduced pattern. Sierra Huichola, Jalisco. Photo courtesy of Iván Trinidad Ahumada Carrillo.

Adult greeri, Sierra Huichol (=Sierra Huichola), Jalisco. Photograph © 2011 Jason Jones.

This fuzzy image was taken in 1964, showing EAL 1170, the first Lampropeltis greeri from the state of Zacatecas. Although referred to at the time as "Lampropeltis mexicana," on the basis of color pattern this snake is clearly referrable to greeri. Photo by Ernest A. Liner, courtesy of G. Salmon.

Adult greeri from near Otinapa, Durango, found in Summer 2006. Photo © C. Rodriguez.