( melanistic garter, Thamnophis elegans )
[This melanistic (opposite of albino) species of garter snake, as first recorded by Capt. Lewis in 1804, is regarded as unique to the Townsend, Montana area.]


Lewis's Black Snake


Lewis and Clark Expedition and 

the Townsend Black Snake

by Troy Helmick

    President Thomas Jefferson wrote Meriwether Lewis very lengthy and detailed instructions1 as the Corps prepared for the Expedition to the Pacific Ocean. Under the heading “Other Objects Worthy of Notice,” Jefferson included:


…the soil & face of the country, it’s growth & vegetable productions …the animals of the country generally, & especially those not known in the U.S., the remains & accounts of any which may be deemed rare or extinct; …times of appearance of particular birds, reptiles or insects.2


   Tuesday July 23, 1805: Captain Meriwether Lewis and the main party of the Expedition proceeded on their mission up the Missouri River with eight dugout canoes. As noted on Clark’s map,3 the party camped that night on a small island in the river three miles north of present-day Townsend in Broadwater County, Montana.  Capt. Lewis recorded in his Journal that day:  


I saw a black snake today about two feet long the belly of which was as black as any other part or as jet itself. it had 128 scuta on the belley and 63 on the tail.4


   The following day—July 24, the party continued up the river past Indian Creek, the Crimson Bluffs, Yorks Islands, then camped on the west side of the river six miles south of Townsend, near Dry Creek. Lewis recorded on that day:


…we observed a great number of snakes about the water of a brown uniform colour, some black and others speckled on the abdomen and striped with black and brownish yellow on the back and sides. The first of these is the largest being about 4 feet long, the second is of that kind mentioned yesterday, and the last is much like the garter snake of our country and about its size. None of these species are poisouous I examined their teeth and found them innocent. They all appear to be fond of the water, to which they fly for shelter immediately on being pursued.5


  Capt. Lewis evidently found the little black snake to be worthy of notice as he measured the length, counted scales and examined the teeth. Worthy of notice it must be, as we are still attempting to determine its identity after more than two hundred years!


Incorrectly Identified


   In The Original Journals of the Lewis and Clark Expedition, Vol. II Part II, Thwaites 1904, a footnote on page 264, Coues misidentified the snake as, “The dark variety of the so-called spreading adder or blowing viper—a species of Heterodon.6


   In a footnote on page 422 of The Journals of the Lewis & Clark Expedition, Volume 4, Gary Moulton, editor., the snake was also misidentified as the “Western Hog-nosed snake, Heterodon nasicus, Burroughs, 276-77; Cutright (LCPN), 427-28.”7


   In We Proceeded On, Volume 34, No. 3 August 2008, (page 22) an article by Kenneth C. Walcheck, MONTANA ZOOLOGICAL DISCOVERIES THROUGH THE EYES OF LEWIS AND CLARK, the snake was again misidentified as a “WESTERN HOG-NOSED SNAKE, Heterodon nasicus. The snake was described by Spencer Fullerton Baird and Charles Girard (1852). Observation date: July 23, 1805.” 8 


   All three of the editors incorrectly identified the snake. Now, more than 200 years after Capt. Lewis described the little black snake, we can finally determine its proper biological classification.9


   In the Montana Outdoors magazine publication, IDENTIFICATION OF MONTANA’S AMPHIBIANS AND REPTILES, by Jim Reichel and Dennis Flath, 1995, two garter snakes are listed as native to the Townsend area: the Common Garter snake, (Thamnophis sirtalis) and the Western Terrestrial, (Thamnophis elegans). Also noted, “...all black individuals are occasionally found.”10 The question then is, does the black snake belong to the T. sirtalis or to the T. elegans species?


Searching for Black Snakes


   Larry Thompson, a Helena, Montana biologist in May of 1983 was searching for the black snake in the Townsend area. In an article in The Townsend Star11 he offered a reward of ten dollars to the first person to provide a living specimen of the black snake, together with information on the exact site and date of capture. We found no record of any snakes captured or rewards paid.


   The Crimson Bluffs Chapter of the Lewis and Clark Trail Heritage Foundation was chartered at Townsend, Montana in 1998. The capture and identification of the Lewis black snake was one of the objectives shared by several of the new chapter members. Progress on the project was very slow until 2003, when a black snake was captured in Townsend and another by the Missouri River west of Townsend. An interested individual from Kalispell, a college Professor from Bozeman and a TV reporter with camera from Helena, all came to see the snakes. We soon had land owners, school teachers, students, sheriff’s deputies, housewives and others searching for black snakes along twenty miles of the Missouri River.


   The chapter contacted Dr. Grant Hokit, Biology Professor at Carroll College in Helena, MT and at his invitation we delivered some snakes to him at the college. He was immediately and eagerly supportive of our effort. He gave us much needed advice on the collecting, care and feeding of garter snakes. We continued to search and collect garter snakes and kept in contact with Dr. Hokit about our progress. We did show live snakes and spoke to students in classrooms and to others at outdoor events. Each year as fall weather approached, we released the captured snakes so they could return to their communal dens sites before winter.


   In spring 2007, Dr. Hokit called us to report that he had students and resources to proceed on with a research project to identify the black snake. We agreed to assist them with hunting and collecting snakes and offered to help in any other way that we could.


Species Identified


   Carroll College students, James T. Van Leuven and Sarah Tomaske came to Townsend with the objective to determine if melanistic garter snakes from the Townsend area belong to T. elegans, T. sirtalis, or neither.


   In his thesis, Survey of Melanistic Garter Snakes by Traditional and Geometric Morphometrics, Van Leuven explains how a total of 80 T. elegans, 20 T. sirtalis and 23 melanistic individual snakes were captured and analyzed.12 Five photographs were taken of each specimen, scale count, linear and geometric morphometrics and other data were recorded for each specimen.13 A scale was clipped on each snake to identify and prevent duplication of data.14 Approximately 2mm of the tip of the tail was clipped and stored for DNA analysis for a separate study in the future.15 Information collected with each specimen included time and date of capture, air temperature, wind conditions, distance to nearest water source, habitat type, morphotype and GPS coordinates.16 All snakes were released near their capture site.17 Van Leuven completed the research and concluded that melanistic individuals in the Townsend area are morphometrically more similar to T. elegans than to T. sirtalis.18


   DNA analysis of the specimens clipped from the snakes and stored by Van Leuven was completed by Carroll College student Kevyn J. Stroebe in 2009. The study, Molecular Genetic Affinities of the Melanistic Western Terrestrial Garter Snake, Thamnophis elegans examined the association between phenotype and species of garter snakes found along the Missouri River near Townsend, MT by analyzing the cytochrome b mitochondrial DNA sequences of Thamnophis elegans (Western Terrestrial Garter Snake), T. sirtalis (Common Garter Snake) and melanistic individuals.19 The results showed that the melanistic snake sequences are more similar to sequences of T. elegans than to those of T. sirtalis.20 The melanistic snakes group with T. elegans in phylogenetic analyses.21 The results support the morphological evidence of Van Leuven (2008) which showed that the melanistic snakes are morphologically more similar to T. elegans than to T. sirtalis.22


   The combined analyses of Kevyn and J.T. is a document in preparation (Melanistic Phenotype of Thamnophis elegans First Described by Captain Meriwether Lewis. Authors: D. Grant Hokit, Jennifer M.O. Geiger, James T. Van Lueven, Kevyn Stroebe) that is being submitted to the scientific journal Northwest Naturalists. The results of the combined analyses provide strong evidence that the melanistic garter snakes reported from Broadwater Co. are morphotypes of T. elegans.23 Supralabial counts, linear morphometrics and molecular phylogenetics all demonstrate the similarities between T. elegans and melanistic individuals while simultaneously describing the distinctiveness of T. sirtalis in the area.24 This conclusion was further supported by the capture of a specimen exhibiting phenotypic mosaicism (Rakyan et al. 2002) with the head and posterior parts in typical color morphology for T. elegans and melanism in other parts.25 Other melanistic individuals were completely black with no discernible dorsal or lateral lines.26


   Based on the results of the analysis of the description by Lewis, and the known distribution of herpetofauna in Montana, we conclude that it was most likely a melanistic individual of T. elegans that Captain Lewis encountered on July 23, 1805 and not a Western Hog-nosed snake.27 His location on that date was less than 10 km from our study site, he described a snake that is “jet black” [sic] in appearance, and his scale counts fit within the range known for T. elegans (Rossman et al. 1996).28 Also, on the subsequent day he mentions a second black snake (“of that kind mentioned yesterday”) within the context of describing numerous encounters with garter snakes (Lewis et al. 2002).29 Conversely, the Western Hog-nosed snake has not been confirmed in Broadwater County.30


   For more information, contact: Dr. Grant Hokit, Department of Natural Sciences, Carroll College, 1601 N. Benton Ave., Helena, MT 59625.


   Troy Helmick is a Charter Member and a Director of the Crimson Bluffs Chapter of the Lewis and Clark Trail Heritage Foundation in Townsend, Montana.



1.  Thomas Jefferson, Jefferson’s Instructions to Meriwether Lewis, Thomas Jefferson Foundation, Inc. Nov., 2003, accessed May 10, 2014,

2. Ibid.

3. Gary E. Moulton, ed., The Journals of the Lewis and Clark Expedition, 11 volumes (Lincoln: University of Nebraska Press, 1983-2001), Vol. 1, Atlas of the Lewis and Clark Expedition, No. 63.

4. Ibid., Vol. 4, p. 421.

5. Ibid., Vol. 4, p. 423.

6. Reuben G. Thwaites, ed., Original Journals of the Lewis and Clark Expedition, 1804-1806, 7 volumes and an atlas (New York, 1904-1905), Vol. II Part II, p. 264.

7. Moulton, Vol. 4, p. 422.

8. Kenneth C. Walcheck, “Montana Zoological Discoveries Through the Eyes of Lewis and Clark,” We Proceeded On, Vol. 34, No. 3, Aug. 2008, p. 22.

9. The detailed biological data referred to in this article came from two college theses and an analysis of the combined theses—all from the Department of Natural Sciences at Carroll College, Helena, MT.

10.  Jim Reichel and Dennis Flath, “Identification of Montana’s Amphibians and Reptiles,” Montana Outdoors, 26.3, May/June 1995, p. 30.

11. Larry Thompson, “Biologist Looking For Garter Snakes,” The Townsend Star, May 12, 1983, p. 1.

12. James T. Van Leuven, “Survey of Melanistic Garter Snakes by Traditional and Geometric Morphometrics,” (B.S. thesis, Carroll College, Helena, MT, April 2008), p. 12.

13. Van Leuven, “Survey Melanistic Garter Snakes,” p. 8.

14. Van Leuven, “Survey Melanistic Garter Snakes,” p. 8.

15. Van Leuven, “Survey Melanistic Garter Snakes,” pp. 8-9.

16. Van Leuven, “Survey Melanistic Garter Snakes,” p. 9.

17. Van Leuven, “Survey Melanistic Garter Snakes,” p. 9.

18. Van Leuven, “Survey Melanistic Garter Snakes,” p. 20.

19. Kevyn J. Stroebe, “Molecular Genetic Affinities of the Melanistic Western Terrestrial Garter Snake, Thamnophis elegans,” (B.S. thesis, Carroll College, Helena, MT, April 2008), p. 3.

20. Stroebe, “Melanistic Garter Snake,” p. 3.

21. Stroebe, “Melanistic Garter Snake,” p. 10.

22. Stroebe, “Melanistic Garter Snake,” p. 11.

23. D. Grant Hokit, Jennifer M. O. Geiger, James T. Van Lueven, Kevyn J. Stroebe, “Melanistic Phenotype of Thamnophis elegans First Described by Captain Meriwether Lewis,” (analysis of two theses in possession of authors, Dept. of Natural Sciences, Carroll College, Helena, MT, [not dated]), p. 7.

24. Hokit, et al., “First Described by Lewis,” p. 7.

25. Hokit, et al., “First Described by Lewis,” p. 7.

26. Hokit, et al., “First Described by Lewis,” p. 7.

27. Hokit, et al., “First Described by Lewis,” p. 8.

28. Hokit, et al., “First Described by Lewis,” p. 8.

29. Hokit, et al., “First Described by Lewis,” p. 8.

30. Hokit, et al., “First Described by Lewis,” p. 8.



Garter Snakes around Townsend, MT
Garter Snakes

 Melanestic Garter Snake in its own enviroment
Melanestic Garter Snake in it's own enviroment