The Gray Wolf is the largest of the wild dogs. Adult male Gray Wolves in Montana weigh around 47 kilograms (104 pounds) and females weigh around 36 kilograms (80 pounds). Males average approximately 186 centimeters (73 inches) in length, while 180 centimeters (70 inches) is the average for females, with the tail compromising a little less than one-third of the total length in both sexes (Foresman 2012). About half the Gray Wolves in Montana are black with the other half gray. Both color phases may be found in a pack or in a litter of pups.
Western Hemisphere Range
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
This species is not migratory but may move seasonally following migrating ungulates within its territory. Gray Wolves also disperse widely. Males in northwestern Montana can move an average of 113 km (70 miles) from their natal territory, and females 77 km (48 miles), before establishing a new territory or joining an existing pack (Boyd and Pletscher 1999). Dispersal peaks twice per year; first in January/February and second, in May/June (Boyd and Pletscher 1999). Some Gray Wolves are known to have dispersed up to 805 km (500 miles). Dispersal has been documented from Canada, Idaho and Wyoming to Montana. Montana Gray Wolves are also known to have dispersed to Canada, Idaho, and Wyoming.
The Gray Wolf exhibits no particular habitat preference except for the presence of native ungulates within its territory on a year-round basis. In Minnesota and Wisconsin, Gray Wolves usually occur in areas with few roads and human disturbance (Thiel 1985, Mech et al. 1988, Mech 1989). Gray Wolves establishing new packs in Montana have demonstrated greater tolerance of human presence and disturbance than previously thought characteristic of this species. They have established territories where prey are more abundant at lower elevations than expected, especially in winter (MTFWP 2003).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: mtnhp.org/requests
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
- Commonly Associated with these Ecological Systems
Forest and Woodland Systems
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Sparse and Barren Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Gray Wolves are opportunistic carnivores that predominantly prey on large ungulates. Main prey items in Montana include deer, Elk, and Moose (MTFWP 2003). Bison are also taken where the ranges of the two species overlap in and around Yellowstone National Park. Domestic livestock such as cattle and sheep are also preyed upon. Gray Wolves may also eat alternative prey, such as rodents, vegetation and carrion. Gray Wolves commonly hunt in packs, but lone animals and pairs are able to kill prey as large as adult Moose (Thurber and Peterson 1993).
In most areas, Gray Wolves are territorial throughout the year. Packs generally consist of a socially dominant pair, their offspring of the previous year, and new pups, although other breeding-age adults that may or may not be related to the alpha pair may also be present (MTFWP 2003). More than 1 female in the pack can breed and give birth to pups. Pup survival when there are multiple litters is highly variable. Pack size varies and may include as few as 3 and as many as 37 (USFWS et al. 2001). In the Glacier National Park area, packs generally include 8 to 12 individuals (Bangs and Fritts 1993). Packs share pup-rearing responsibilities including food provisioning and tending pups at the den or rendezvous sites (MTFWP 2003). Pack activity is centered on the den site and nearby rendezvous sites from late April until September (MTFWP 2003). Lone Gray Wolves may move through territories of established packs (Thurber and Peterson 1993). Pack territories are dynamic and change from year to year depending on prey availability, Gray Wolf populations, and relationships with neighboring packs.
Summer home ranges are smaller than winter ranges; the annual range may be up to several hundred square kilometers (km). In the Glacier National Park area, territory size averages around 780 square kilometers (301 square miles)(Bangs and Fritts 1993). Gray Wolves may occasionally move several hundred kilometers, especially dispersing young. In Minnesota, most dispersers left when they were 11 to 12 months old; dispersal occurred mainly in February to April and October to November; 35% of known-age Gray Wolves remained in their natal territory for more than 2 years (Gese and Mech 1991). Average territory size in northwestern Montana was 220 square kilometers (185 square miles) but was highly variable (USFWS et al. 2002). Average territory size for Yellowstone Gray Wolves was larger, averaging 891 square kilometers (344 square miles) (USFWS et al. 2002).
Gray Wolves are generally not instrumental in causing prey declines but their effect varies with other environmental circumstances. In Quebec, winter weather appeared to affect the deer population trend more than did Gray Wolf predation (Potvin et al. 1992). In south-central Alaska, Gray Wolf predation may have limited Caribou recruitment (Bergerud and Ballard 1988), though winter starvation also was proposed as a significant population control. Gray Wolves may take livestock as secondary prey when deer fawns (the primary summer prey) are less vulnerable due to better prenatal nutrition resulting from mild winter (USFWS 1990). In Minnesota, snow-induced changes in deer distribution and mobility resulted in changes in Gray Wolf movement patterns, sociality, and feeding behavior. When snow was shallow, Gray Wolves traveled farther and more often, spent less time with pack members, and used conifer cover less and killed fewer deer (Fuller 1991). Gray Wolves have been implicated in declines in Elk numbers around Yellowstone National Park. This relationship is still being studied in conjunction with other environmental factors.
In Montana, Gray Wolves breed in mid- to late February (Boyd et al. 1993), with gestation lasting about 63 days (MTFWP 2003). A female can only give birth once a year. Breeding usually occurs between the dominant male and female in the pack and Gray Wolves normally do not breed until they are at least 22 months old (Mech 1970). Occasionally, more than 1 female in a pack may breed, resulting in more than 1 litter per pack (Ballard et al 1987). Young are typically born in late April in an underground burrow that has been abandoned by another mammal or dug by Gray Wolves. In northwestern Montana litter sizes range from 1 to 9 with a mean of 5.3 (MTFWP 2003). Pups emerge from the den in about 3 weeks and are weaned in 50 days (also reported as 5 weeks). Young vacate the den when they are about 3 months old (Hoffmeister 1986) and move to a series of rendezvous sites throughout the pack's territory. The pups are large enough to travel with the entire pack by September. Some offspring remain with the pack; others disperse as they mature. Lone Gray Wolves generally do not successfully rear young, but they may if food is abundant (Boyd and Jimenez 1994).
Pup survival is variable and influenced by a number of factors including disease, predation, and nutrition. In Montana, pup mortality was most often attributed to human causes (Pletscher et al. 1997), but canine parvo virus was strongly suspected as a main factor in low pup survival in Yellowstone Gray Wolves in 1999 (MTFWP 2003).
Although Gray Wolves dispersing from Canada were occasionally observed, they were essentially extirpated from Montana and the rest of the western United States in the early 1900s primarily due to conflicts with people. As a result, they were listed as Endangered under the Endangered Species Act in 1967 (32 FR 4001). Gray Wolves started recolonizing the area around Glacier National Park in 1979 and the first den documented in Montana in over 50 years was found in Glacier National Park in 1986. In 1995 and 1996 Gray Wolves were reintroduced into Yellowstone National Park and central Idaho. Wolves resulting from these reintroductions and those dispersing naturally from northwestern Montana and Canada have now colonized most of western Montana. Gray wolves reached biological recovery goals for the Northern Rocky Mountains at the end of 2002 and were delisted in May of 2009 (74 FR 15123 15188). However, they were relisted as Endangered/Experimental Nonessential on August 5, 2010 by federal court order. Then, on May 5, 2011, they were again removed from the Endangered Species Act by the Secretary of the Interior at the direction of the President of the United States and Congress under a rider associated with the Department of Defense and Full-Year Appropriations Act of 2011 (76 FR 25590-25592).
Montana Fish, Wildlife and Parks is the lead agency for Gray Wolves, including population monitoring, resolving wolf-livestock conflicts, research, and public outreach. Federal regulations continue to guide Montana Fish, Wildlife, and Parks management practices. You can access a variety of detailed information on Gray Wolves in Montana from the Montana Fish, Wildlife, and Park's Wolf Program
- Literature Cited AboveLegend: View Online Publication
- Ballard, W.B., J.S. Whitman and C.L. Gardner. 1987. Ecology of an exploited wolf population in south-central Alaska. Wildl. Monogr. 98. 54 p.
- Bangs, E.E. and S.H. Fritts. 1993. Reintroduction of gray wolves to Yellowstone National Park and central Idaho. Endangered Species Tech. Bull. 18(3):1, 18-20.
- Bergerud, A.T. and W.B. Ballard. 1988. Wolf predation on caribou: the Nelchina herd case history, a different interpretation. J. Wildl. Manage. 52:344-357.
- Boyd, D.K. and D.H. Pletscher. 1999. "Characteristics of Dispersal in a Colonizing Wolf Population in the Central Rocky Mountains". The Journal of Wildlife Management. 63 (4): 1094-1108.
- Boyd, D.K. and M.D. Jimenez. 1994. Successful rearing of young by wild wolves without mates. J. Mamm. 75(1): 13-17.
- Boyd, D.K., R.P. Ream, D.H. Pletscher, and M.W. Fairchild. 1993. Variation in denning and parturition dates of a wild Gray Wolf, Canis lupus, in the Rocky Mountains. The Canadian Field-Naturalist. 107(3): 359-360.
- Fuller, T.K. 1991. Effect of snow cover on wolf activity and prey selection in north central Minnesota. Canadian J. Zoology 69:283-287.
- Gese, E.M. and L.D. Mech. 1991. Dispersal of wolves (Canis lupus) in northeastern Minnesota, 1969-1989. Canadian Journal of Zoology 69:2946-2955.
- Hoffmeister, D.F. 1986. Mammals of Arizona. Univ. Arizona Press and Arizona Game and Fish Dept. 602 pp.
- Mech, L.D. 1970. The wolf - the ecology and behavior of an endangered species. Natural History Press, Doubleday, New York. 384 p.
- Mech, L.D. 1989. Wolf population survival in an area of high road density. Am. Midl. Nat. 121: 387-389.
- Mech, L.D., S.H. Fritts, G.L. Radde, and W.J. Paul. 1988. Wolf distribution and road density in Minnesota. Wildl. Soc. Bull. 16(1): 85-87.
- Montana Department of Fish, Wildlife, and Parks. 2003. Montana Gray Wolf Conservation and Management Plan. Draft Environmental Impact Statement. Unpublished report. 275 pp.
- Pletscher D.H., R.R. Ream, D.K. Boyd, M.W. Fairchild, and K.E. Kunkel. Population Dynamics of a Recolonizing Wolf Population. The Journal of Wildlife Management, 61(2), 459–465.
- Potvin, F., H. Jolicoeur, L. Breton, and R. Lemieux. 1992. Evaluation of an experimental wolf reduction and its impact on deer in Papineau-Labelle Reserve, Quebec. Canadian J. Zoology 70:1595-1603.
- Thiel, R.P. 1985. Relationship between road densities and wolf habitat suitability in Wisconsin. Am. Midl. Nat. 113: 404-407.
- Thurber, J.M., and R.O. Peterson. 1993. Effects of population density and pack size on the foraging ecology of gray wolves. J. Mammalogy 74:879-889.
- U.S. Fish and Wildlife Service. 1990. Endangered and threatened species recovery program: report to Congress. 406 pp.
- USFWS, Nez Perce Tribe, National Park Service, and USDA Wildlife Services. Rocky Mountain Wolf Recovery 2001 Annual Report. USFWS, Helena, MT.
- USFWS, Nez Perce Tribe, National Park Service, and USDA Wildlife Services. Rocky Mountain Wolf Recovery 2002 Annual Report. USFWS, Helena, MT.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Adelman, E.B. 1979. A survey of the nongame mammals in the Upper Rattlesnake Creek drainage of western Montana. M.S. thesis. University of Montana, Missoula. 129 pp.
- Allen, T.D.H. 2011. Wildlife guards for deer and Black Bear. M.Sc. Thesis. Bozeman, Montana: Montana State University. 71 p.
- Andersen, K. W., and J. K. Jones, Jr. 1971. Mammals of northwestern South Dakota. Univ. Kan Mus. Nat. Hist. Pub. 19:361-393.
- Anonymous. 1993. Forensics Lab Identifies Animals Killed in Wyoming and North Dakota as Wolves. Endangered Species Technical Bulletin 18(1): 3, 15.
- Anonymous. 1995. Yellowstone Wolves Bear Pups. Endangered Species Technical Bulletin 20(4): 4-5.
- Atwell, G. 1964. Wolf predation on calf moose. J. Mammal. 45:313-314.
- Balser, D. S., R. Evans, D. L. Flath, D. Mcintoch, M. M. Meagher, N. R. Miner, K. Norrie, R. R. Ream, and R. K. Turner, 1980, Northern Rocky Mountain Wolf Recovery Plan
- Bangs, E. E., S. H. Fritts, J. A. Fontaine, D. W. Smith, K. M. Murphy, C. M. Mack, and C. C. Niemeyer. 1998. Status of gray wolf restoration in Montana, Idaho, and Wyoming. Wildlife Society Bulletin 26(4):785-798.
- Becker, M.S. 2008. Applying predator-prey theory to evaluate large mammal dynamics: Wolf predation in a newly-established multiple-prey system. Ph.D. Dissertation. 148 p.
- Bergman, E.J. 2003. Assessment of prey vulnerability through analysis of wolf movements and kill sites. M.Sc. Bozeman, MT: Montana State University. 48 p.
- Bjorge, R.R., and J.R. Gunson. 1989. Wolf, Canis lupus, population characteristics and prey relationships near Simonette River, Alberta. Canadian Field-Naturalist 103:327-334.
- Boyce, M. S. 1990. Wolf recovery for Yellowstone National Park: a simulation model. Pp. 3.05-3.58 in Wolves for Yellowstone? A report to the United States Congress. Vol. II. USDI National Park Service, Yellowstone National Park.
- Boyd, D. 1982. Coyote-wolf interactions with regard to food habits and movements in the North Fork Flathead drainage. M.S. thesis, University of Montana, Missoula. 115 pp.
- Boyd, D. 1982. Food habits and spatial relations of coyotes and a lone wolf in the Rocky Mountains. M.S. thesis. University of Montana, Missoula. 115 pp.
- Brennan, A.L. 2014. Linking patterns in elk aggregation and brucellosis to variation in group size, land use, climate and wolves. Ph.D. Dissertation. Bozeman, Montana: Montana State University. 179 p.
- Brittan, M.R. 1953. A note concerning wolves in Glacier National Park, Montana. J. Mamm. 34:127-129.
- Carbyn, L. 1983. Wolves in Canada and Alaska. Ottawa. 135 pp.
- Ciucci, P., and L. D. Mech. 1992. Selection of wolf dens in relation to winter territories in northeastern Minnesota. J. Mammal. 73: 899-905.
- Cohn, J. P. 1990. Endangered wolf population increases. BioScience 40(9):628-632.
- Confluence Consulting Inc. 2010. Montana Department of Transportation Wetland Mitigation Monitoring Reports (various sites). MDT Helena, MT.
- Curnow, E. E. 1969. The history of the eradication of the wolf in Montana. M.S. thesis. University of Montana, Missoula. 99 pp.
- Day, Gary L. 1981. The status and distribution of wolves in the northern Rocky Mountains of the United States. M.S. thesis. Univ. of Montana, Missoula. 130 pp.
- Diamond, S. J., and P. Finnegan. 1991. Wolf movements and food habits on the Rocky Mountain front: annual report 1991. USDA For. Serv., Lewis & Clark National Forest, Great Falls. 17 pp.
- Diamond, S. J., and P. Finnegan. 1992. Wolf movements and food habits on the Rocky Mountain front: 1992 annual report. USDA For. Serv., Lewis & Clark National Forest, Great Falls. 10 pp.
- Dillard, S.L. 2019. Restoring semi-arid lands with microtopography. M.Sc. Thesis. Bpzeman, MT: Montana State University. 97 p.
- Dunkley, S.L. 2011. Good animals in bad places: Evaluating landscape attributes associated with Elk vulnerability to Wolf predation. M.Sc. Thesis. Bozeman, MT: Montana State University. 129 p.
- Flath, D. L. 1975. The wolf. Montana Outdoors 6(5):42-45.
- Flath, D. L. 1979. The nature and extent of reported wolf activity in Montana. Page 25 in Proc. Montana Chap., The Wildl. Soc., Missoula.
- Flath, D.L. 1979. Nongame species of special interest or concern: Mammals, birds, reptiles, amphibians, fishes. Wildlife Division, Montana Department of Fish and Game. Helena, MT.
- Forbes, G. J., and J. B. Theberge. 1996. Response by wolves to prey variation in central Ontario. Canadian Journal of Zoology 74:1511-1520.
- Foresman, K.R. 2001. The wild mammals of Montana. American Society of Mammalogists, Special Publication Number 12. Lawrence, KS. 278 pp.
- Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
- Fritts, S.H. and L.D. Mech. 1981. Dynamics, movements, and feeding ecology of a newly protected wolf population in northwestern Minnesota. Wildl. Monogr. No. 80:1-79.
- Garton, E. O., R. L. Crabtree, B. B. Ackerman and G. Wright. 1990. The potential impact of a reintroduced wolf population on the northern Yellowstone elk herd. Pp. 3.61-3.91 in Wolves for Yellowstone? A report to the United States Congress, Vol. II. USDI National Park Service, Yellowstone National Park, Wyo. 749 pp.
- Gower, C.G. 2009. Behavioral responses of Elk to winter Wolf predation risk in the Madison Headwaters Area, Yellowstone National Park. Ph.D. Dissertation. 193 p.
- Grigg, J.L. 2007. Gradients of predation risk affect distribution and migration of a large herbivore. M.Sc. Thesis. Bozeman, MT: Montana State University. 94 p.
- Gude, J.A. 2004. Applying risk allocation theory in a large mammal predator-prey system: elk-wolf behavioral interactions. M.Sc. Thesis. Bozeman, MT: Montana State University. 52 p.
- Hall, E.R. 1981. The mammals of North America, volumes I and II. John Wiley & Sons, New York, NY. 1181 pp.
- Harrington, F. H. and P. C. Paquet. 1982. Wolves of the world: perspectives of behavior, ecology, and conservation. Noyes Publications, Park Ridge, New Jersey.
- Harris, R. and R. Ream. 1983. A method to aid in discrimination of tracks from wolves and dogs. Canad. Wildlife Service Report Series, No. 45: 120-124.
- Harris, R. B. 1977. Wolf ecology project. P. 37 in K. L. McArthur, comp., 1976 Annual Research Summary, Glacier National Park. Unpubl. Rep., USDI National Park Service, Glacier National Park. 64 pp.
- Heard, D. C., and T. M. Williams. 1992. Distribution of wolf dens on migratory caribou ranges in the Northwest Territories, Canada. Canadian J. Zoology 70:1504-1510.
- Hoffmann, R.S. and D.L. Pattie. 1968. A guide to Montana mammals: identification, habitat, distribution, and abundance. University of Montana, Missoula. 133 pp.
- Hoffmann, R.S., P.L. Wright, and F.E. Newby. 1969. The distribution of some mammals in Montana. I. Mammals other than bats. Journal of Mammalogy 50(3): 579-604.
- Holbrook, J.D., J.R. Squires, L.E. Olson, N.J. DeCesare, and R.L. Lawrence. 2017. Understanding and predicting habitat for wildlife conservation: the case of Canada Lynx at the range periphery. Ecosphere 8(9):e01939.
- Jaffe, R. 2001. Winter wolf predation in an elk-bison system in Yellowstone National Park, Wyoming. M.Sc. Thesis. Bozeman, MT: Montana State University. 68 p.
- Jimenez, M. 1992. Establishment of and prey selection by a new wolf pack in the Wigwam River drainage. M.S. thesis, University of Montana, Missoula.
- Johnson, A. S. 1991. Will lobo come home? Defenders 66(1): 10-17.
- Johnson, M. R. 1992. The disease ecology of brucellosis and tuberculosis in potential relationship to Yellowstone wolf populations. Pp. 5-69 to 5-92 in Wolves for Yellowstone?· Rep. to U.S. Congress, Vol. IV Ressearch and Analysis, USDI National Park Service, Yellowstone National Park, WY. 750 pp.
- Johnson, M. R. 1992. The potential role of rabies in relation to possible Yellowstone wolf populations. Pp. 5-45 to 5-68 in Wolves for Yellowstone? Rep. to U.S. Congress, Vol. IV Ressearch and Analysis, USDI National Park Service, Yellowstone National Park, WY. 750 pp.
- Kaley, M. R. 1976. Summary of wolf observations since spring, 1975. Unpubl. Rep., USDI National Park Service, Glacier National Park. 10 pp.
- Kaminski, T. and J. Hansen. 1984. Wolves of central Idaho. MT Coop. Wildl. Res. Unit, Missoula. 197 pp.
- Kennedy, P.K., et al. 1991. Genetic variability in natural populations of the gray wolf, Canis lupus. Canadian Journal of Zoology 69:1183-1188.
- Klinghammer, E. (ed). 1978. The behavior and ecology of wolves. Garland STPM Press, New York. 588 pp.
- Koel, T.M., L.M. Tronstad, J.L. Arnold, K.A. Gunter, D.W. Smith, J.M. Syslo, and P.J. White. 2019. Predatory fish invasion induces within and across ecosystem effects in Yellowstone National Park. Science Advances 5:eaav1139.
- Koth, B., D. W. Lime and J. Vlaming. 1990. Effects of restoring wolves on Yellowstone area big game and grizzly bears. Pp. 4.53-4.81 in Wolves for Yellowstone? A report to the United States Congress, Vol. II. USDI National Park Service, Yellowstone National Park, WY.
- Kunkel, K. and D.H. Pletscher. 2001. Winter Hunting Patterns of Wolves in and Near Glacier National Park, Montana. The Journal of Wildlife Management 65(3):520-530.
- Lampe, R.P., J.K. Jones Jr., R.S. Hoffmann, and E.C. Birney. 1974. The mammals of Carter County, southeastern Montana. Occa. Pap. Mus. Nat. Hist. Univ. Kan. 25:1-39.
- Lehman, N., et al. 1991. Introgression of coyote mitochondrial DNA into sympatric North American gray wolf populations. Evolution 45:104-119.
- Licht, D.S. and S.H. Fritts. 1994. Gray wolf (Canis lupus) occurrences in the Dakotas. American Midland Naturalist. 132:74-81.
- Liley, S.G. 2007. Elk (Cervus elaphus) vigilance levels in response to predation risk from wolves. M.Sc. Thesis. Bozeman, MT: Montana State University. 50 p.
- Lindler, B. 1986. The magic pack: a wolf come-back in the North Fork. Montana Magazine, Jan.-Feb.:27-30.
- Mack J. A., and F. J. Singer. 1992. Predicted effects of wolf predation on Northern range elk, mule deer, and moose using POP-II models. Pp. 4-43 to 4-70 in Varley, I. D.' and W. G. Brewster, eds. Wolves for Yellowstone? A report to the United States Congress, vol. IV, Research and Analysis. Natl. Park Serv., Yellowstone National Park, WY. 749 pp.
- Mack, I. A., F. J. Singer, and M. E. Messaros. 1990. The ungulate prey base for wolves in Yellowstone National Park II: elk, mule deer, white-tailed deer, moose, bighorn sheep, and mountain goats in the areas adjacent to the park. Pp. 2-41 to 2218 in Wolves for Yellowstone A report to the United States Congress, Vol. 2, Research and Analysis. Natl. Park Serv., Yellowstone National Park, WY.
- Mack, J. A., W. G. Brewster, and S. H. Fritts. 1992. A review of wolf depredation on livestock and implications for the Yellowstone area. Pp. 5-21 to 5-42 in J. D. Varley and W. G. Brewster, eds., Wolves for Yellowstone? A report to the United States Congress, Vol. IV, Research and Analysis. USDI National Park Service, Yellowstone National Park, Wyo. 749 pp.
- Martinka, C. J. 1976. Planning guidelines for the conservation of northern Rocky Mountain wolves in Glacier National Park. Unpubl. Rep., USDI National Park Service, Glacier National Park. 3 pp.
- Matteson, M. 1992. Wolf denning sites in southwestern Montana. M.S. thesis, University of Montana, Missoula.
- Mattson, U. 1984. Search for wolves. Persimmon Hill 13(3):37-51.
- Mattson, U. and R. R. Ream 1978. Wolf ecology project. Pp. 51-52 in K. L. McArthur, comp., 1977 Annual Research Summary. Unpubl. Rep., USDI National Park Service, Glacier National Park. 62 pp.
- Mattson, U., and R. R. Ream. 1978. Current status of the gray wolf (Canis lupis) in the Rocky Mountain Front, July, 1978. Unpubl. Rep., Wolf Ecology Project, University of Montana, Missoula. 18 pp.
- Mech, L.D. 1974. Canis lupus. Mamm. Species No. 37. 6 pp.
- Messer, Mathew Adam. 2003. Identifying large herbivore distribution mechanisms through application of fine-scale snow modeling. M.Sc. Thesis. Bozeman, MT: Montana State University. 46 p.
- Minta, S. C., comp. 1990. Annotated wolf bibliography for the northern Rocky Mountains. USDA Forest Service and Northern Rockies Conservation Cooperative. Flathead National Forest, Kalispell. 465 pp.
- Mladenoff, D. J., R. G. Haight, T. A. Sickley, and A. P. Wydeven. 1997. Causes and implications of species restoration in altered ecosystems. BioScience 47(1):21-31.
- Montana Gray Wolf Conservation and Management Plan; March 2003
- Montana Interagency Wolf Working Group. 1991. 1990 Annual Report. 29 pp.
- Montana Outfitters & Guides Association. Montana Fish, Wildlife & Parks., 2000, Predator management in Montana. Symposium proceedings, January 8, 2000.
- Murie, A. 1944. The wolves of Mt. McKinley. National Park Service, Fauna Ser. 5, 238 pp.
- Northern Rocky Mountain Wolf Recovery Team. 1980. Northern Rocky Mountain wolf recovery plan interagency report. 67 pp.
- Northern Rocky Mountain Wolf Recovery Team. 1980. Northern Rocky Mountain wolf recovery plan interagency report. 67 pp.
- Oechsli, L.M. 2000. Ex-urban development in the Rocky Mountain West: consequences for native vegetation, wildlife diversity, and land-use planning in Big Sky, Montana. M.Sc. Thesis. Montana State University, Bozeman. 73 p.
- Peek, J. M., and D. J. Vales. 1989. Projecting the effects of wolf predation on elk and mule deer in the East Front portion of the Northwest Montana Recovery Area. Forest, Wildl. and Range Exp. Sta.: University of Idaho, Moscow, Idaho. 89 pp.
- Peterson, R. O., and R. E. Page. 1988. The rise and fall of Isle Royale wolves, 1975-1986. J. Mammalogy 69:89-99.
- Pletscher, D. H., M. W. Fairchild, and D. K. Boyd. 1989. Wolf ecology project. Monthly Prog. Reps., Jan.-Mar., School of Forestry, University of Montana, Missoula.
- Rachael, J. 1991. Mortality and seasonal distribution of white-tailed deer in an area recently colonized by wolves. In K. Aune, comp., Proc. Mont. Chapt., The Wildl. Soc., Bozeman.
- Ream, R. R. 1981. The status of gray wolves in both the Glacier National Park area and southeastern Alberta. P. 13 in Research/Management Report Series No.3, Glacier National Park, West Glacier. 13 pp.
- Ream, R. R. 1984. The wolf is at our door: population recovery in the northern Rockies. Western Wildlands 10(2):2-7.
- Ream, R. R. 1985. Wolf ecology project. Annual Rep., July 1984 - June 1985. Montana Coop. Wildl. Res. Unit. University of Montana, Missoula.
- Ream, R. R. and U. I. Mattson. 1982. Wolf status in the Northern Rockies. Pp. 362-381 in: Harrington, F. H. and P. C. Paquet, (eds.), Wolves of the world: perspectives of behavior, ecology, and conservation. Noyes Publ., NJ.
- Ream, R. R., and D. H. Pletscher. 1990. Wolf ecology project. P. 50 in K. Dimont, comp., Science in Glacier National Park, 1990. Glacier Natural History Association, West Glacier. 52 pp.
- Ream, R. R., and M. W. Fairchild 1985. Wolf ecology project. Prog. Rep., July-September, 1985, Montana Department of Fish, Wildlife and Parks, Helena. 2 pp.
- Ream, R. R., and U. I. Mattson. 1979. Wolf identification: a field guide. 12 pp.
- Ream, R. R., D. H. Pletscher, D. K. Boyd and M. W. Fairchild. 1989. Population dynamics and movements of recolonizing wolves in the Glacier National Park area. Unpubl. Rep., Mont. For. and Conserv. Exp. Sta., School of Forestry, University of Montana, Missoula. 25 pp.
- Ream, R. R., D. H. Pletscher, D. K. Boyd and M. W. Fairchild. 1989. Wolf ecology in the North Fork Flathead River and Wigwam River drainages 1989 progress report. Pp. 40-41 in K. Dimont, comp., 1989 Science Summary, Glacier National Park, Glacier Natural History Association, West Glacier. 49 pp.
- Ream, R. R., D. H. Pletscher, M. W. Fairchild, and D. K. Boyd. 1987. Wolf ecology project. Monthly Prog. Reps., Jul.-Dec., School of Forestry, University of Montana, Missoula.
- Ream, R. R., D. H. Pletscher, M. W. Fairchild, and D. K. Boyd. 1988. Winter food habits of wolves in the North Fork of the Flathead, Montana and British Columbia. P. 3 in Proc. Mont. Chapt., The Wildl. Soc., Lewistown. 23 pp.
- Ream, R. R., D. H. Pletscher, M. W. Fairchild, and D. K. Boyd. 1988. Wolf ecology project. Monthly Prog. Reps., Jan.-Dec., School of Forestry, University of Montana, Missoula.
- Ream, R. R., D. H. Pletscher, M. W. Fairchild, and D. K. Boyd. 1989. Wolf ecology project. Monthly Prog. Reps., Apr.-Aug., School of Forestry, University of Montana, Missoula.
- Ream, R. R., D. H. Pletscher, M. W. Fairchild, and D. K. Boyd. 1989. Wolf ecology project. Quart. Prog. Rep., Sep.-Nov., School of Forestry, University of Montana, Missoula. 3 pp.
- Ream, R. R., D. K. Boyd, S. Gaughan, C. Schmidt, and B. Giddings. 1980. Wolf ecology project. Pp. 51-52 in K. L. McArthur, comp., 1979 Annual Research Summary. Unpubl. Rep., USDI National Park Service, Glacier National Park. 54 pp.
- Ream, R. R., M. W. Fairchild, and D. K. Boyd 1985. Wolf ecology project. Prog. Rep., Feb-Jun., School of Forestry, University of Montana, Missoula. 3 pp.
- Ream, R. R., M. W. Fairchild, and D. K. Boyd. 1985. Wolf ecology project. Prog. Rep., Dec., Montana Department of Fish, Wildlife and Parks, Helena. 2 pp.
- Ream, R. R., M. W. Fairchild, and D. K. Boyd. 1986. Wolf ecology project. Prog. Rep., March 1986, Montana Department of Fish, Wildlife and Parks, Helena. 2 pp.
- Ream, R. R., M. W. Fairchild, and D. K. Boyd. 1987. Wolf ecology project. Monthly Prog. Reps., Jan.-Jun., School of Forestry, University of Montana, Missoula.
- Ream, R., Fairchild, M., Boyd, D. and A. Blakesley. 1989. First wolf den in western U.S. in recent history. Northwestern Naturalist 70: 39-40.
- Ream, R.R. 1986. Wolf movement in southern Alberta. National Geographic Society Res. Rep. Vol. 21:405-409.
- Ream, R.R., R.B. Harris, J. Smith, and D. Boyd. 1985. Movement patterns of a lone wolf (Canis lupus) in unoccupied wolf range, southeastern British Colombia. Can. Field Nat. 99(2):234-239.
- Reid, F. 2006. Peterson Field Guide to Mammals of North America, 4th Edition. Houghton Mifflin Company: Boston and New York, 608 pp.
- Robbins, J. 1982. Return of the wolf: can Montana recapture its special wildness? Montana Magazine, Jan. :60-64.
- Robbins, J. 1986. Wolves across the border. Nat. Hist. 95(5): 6-15.
- Roybal, J.P. 1998. Winter mortality in the Northern Yellowstone Elk herd 1988-1990. M.Sc. Thesis. Bozeman, MT: Montana State University. 191 p.
- Rust, H. J. 1946. Mammals of northern Idaho. J. Mammal. 27(4): 308-327.
- Sands, J.L. 2001. Stress hormones and social behavior of wolves in Yellowstone National Park. M.Sc. Thesis. Bozeman, MT: Montana State University. 51 p.
- Scott, M.D. and S.A. Scott. 1984. Taxonomy of the dog and wolf: a paradox of dynamic morphology and stable behavior. Proc. 20th Ann. Meeting, Animal Behavior Society, :62.
- Sime, C. 2006. Wolf Conservation and Management Plan, Final Project Performance Report.
- Singer, F. J. 1975. Status and history of timber wolves in Glacier National Park, Montana. [Unpublished report]. 17 pp. Presented at the Symposium on Wolf Behavior and Ecology in Wilmington, North Carolina.
- Singer, F. J. 1975d. The history and status of wolves in northern Glacier National Park, Montana. Glacier National Park Scientific Paper No.1, West Glacier, Montana.
- Singer, F. J. 1990. The ungulate prey base for wolves in YelIowstone National Park I: five species on the northern range, elk parkwide. Pp. 2.5-2.37 in Wolves for YelIowstone? A report to the United States Congress. Vol. II: research and analysis. USDI National Park Service, YeIlowstone National Park, WY.
- Singer, F. J. 1991. Some predictions concerning a wolf recovery into Yellowstone National Park: How wolf recovery may affect park visitors, ungulates and other predators. Trans. 56th N. Amer. Wildl. & Nat. Res. Conf. 56:567-583.
- Singleton, P. H. 1995. Winter habitat selection by wolves in the North Fork of the Flathead River Basin, Montana and British Columbia. M.S. thesis. University of Montana, Missoula. 116 pp.
- Theberge, J. B. 1992. Corrected drafting error in Figure 1, page 461. Canadian Field-Naturalist 106(1): 138.
- Theberge, J. B. 1991. Ecological classification, status, and management of the gray wolf, Canis lupus, in Canada. Canadian Field-Naturalist 105:459-463.
- Thompson, W.K. 1949. A study of marten in Montana. Proc. West. Assoc. State Game and Fish Comm. 29:181-188.
- Tilt, W., R. Norris and A. S. Eno. 1987. Wolf recovery in the northern Rocky Mountains. Publ. booklet, National Audubon Society, National Fish and Wildlife Foundation, Washington, DC. 31 pp.
- Tucker, P. and D.H. Pletcher. 1989. Attitudes of hunters and residents toward wolves in northwestern Montana. Wildlife Soc. Bull. 17: 509-514.
- Tucker, P., Davis, D. and R. Ream. 1990. Wolves: identification, documentation, population monitoring and conservation considerations. Nat'l Wildlife Fed., Missoula, MT. 25pp.
- TVX Mineral Hill Mine, Amerikanuak, Inc., Gardiner, MT., 2002, Yearly summary of wildlife observation reports. 1990-2002 Letter reports.
- Tweten, R.G. 1984. Baseline survey of furbearing mammals within the South Fork drainage Sun River, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 63 p.
- U. S. Fish and Wildlife Service. 2000. Proposal to reclassify and remove the Gray Wolf from the list of endangered and threatened wildlife in portions of the conterminous United States; proposal to establish three special regulations for threatened Gray Wolves. Federal Register 65:43450-43496.
- U.S. Fish and Wildlife Service (USFWS). 1994. Proposed establishment of a nonessential experimental population of gray wolf in Yellowstone National Park in Wyoming, Idaho, and Montana. Federal Register 59(157:42108-42128. 16 August 1994.
- U.S. Fish and Wildlife Service. 1988. Interim wolf control plan, northern Rocky Mountains of Montana and Wyoming. Fish and Wildlife Enhancement Office, Helena. 29 pp.
- U.S. Fish and Wildlife Service. 1989. Wolf recovery in Montana: 1st annual report. Fish & Wildlife Enhancement Office, Helena. 26pp.
- U.S. Fish and Wildlife Service. 1990. Draft revised recovery plan for the eastern timber wolf. 93 pp.
- U.S. Fish and Wildlife Service. 1994. The reintroduction of gray wolves to Yellowstone National Park and central Idaho. Final Environmental Impact Statement.
- U.S. Forest Service, Kootenai National Forest. Montana Dept. of State Lands., 1978?, Final Environmental Impact Statement. Proposed Plan of Mining and Reclamation. Troy Project, Asarco, Inc., Lincoln County, Montana. Vol. III.
- US Fish and Wildlife Service, , A Summary of the Northern Rocky Mountian Wolf Recovery Plan
- USDI National Park Service., 2000, Bison Management for the State of Montana and Yellowstone National Park. Final Environmental Impact Statement for the Interagency Bison Management Plan for the State of Montana and Yellowstone National Park. Vol. I. August 2000.
- Walter, D. 1986. Wolf wars. Montana Magazine, Jan.-Feb. :22-26.
- Wayne, R. K., et al. 1992. Mitochondrial DNA variability of the gray wolf: genetic consequences of population decline and habitat fragmentation. Conservation Biology 6:559-569.
- Weaver, J. 1986. Of wolves and grizzly bears. Western Wildlands (Fall):27-29.
- Weckwerth, R. P. 1957. The relationship between the marten population and the abundance of small mammals in Glacier National Park. M.S. thesis. University of Montana, Missoula. 76 pp.
- Wilson, P. J., S. Grewal, I. D. Lawford, J.N.M. Heal, A. G. Granacki, D. Pennock, J. B. Theberge, M. T. Theberge, D. R. Voigt, W. Waddell, R. E. Chambers, P. C. Paquet, G. Goulet, D. Cluff, and B. N. White. 2000. DNA profiles of the eastern Canadian wolf and the red wolf provide evidence for a common evolutionary history independent of the gray wolf. Canadian Jounal of Zoology 78:2156-2166.
- Winnie, J.A., Jr. 2006. Behavioral responses of Elk (Cervus elaphus) to the threat of Wolf (Canis lupus) predation. Ph.D. Dissertation. Bozeman, MT: Montana State University. 80 p.
- Wuerthner, G. 1986. Wolves return to Montana. High Country News 18(3):10-12.
- Additional Sources of Information Related to "Mammals"