Fortymile
- Herd size (2025) 24,000 – 28,000. (estimate from Alaska Department of Fish and Game based on 2024 photocensus)
The Fortymile herd migrates between Alaska and Yukon. It was once estimated at about 600,000, and its range stretched from Whitehorse to Anchorage. By 1974, the herd was estimated at about 4,000, and it stopped migrating to Yukon. Conservation actions, including hunting restrictions and the sterilization of wolf packs were taken and the herd grew, although recent research suggests that wolf control was not a significant factor in the herd’s increase. By 2002 it was once again migrating into Yukon. In 2017 the estimated herd size was 71,000. The Alaska Department of Fish and Game says "The herd began to show signs of declining nutritional status after it exceeded 50,000 caribou in 2010." In summer 2022, the Department estimated the herd size at 40,000. Increased hunting quotas had been set by the Alaskan government in the previous two years to take the strain off perceived overpopulation. After it's new (2022) population estimate, the Department said, "department staff continued to observe low productivity in the herd this spring and above average mortality of newborn calves this summer, indicating continuing nutritional stress and low potential for herd growth."
Related news
New Season Dates and Hunt Quota for Fall Fortymile Caribou Hunt
This media advisory for hunting quotas in Alaska also contain the news that this herd, shared between Alaska and Yukon, has declined further since the last published population estimates. Based on a pgotocensus from last year, the Alaskan Department of Fish and Game now estimates herd size at 24,000 - 28,000. The previous estimate from 2022 put the herd at about 40,000. Hunting in Alaska is still being allowed, but is retricted to 525 caribou, and all bulls.
17 July 2025 | Alaska department of fish and game
The Great Video Reveal: Emerging Tech Tracks What Caribou Do
An online article about the use of video on collars to monitor caribou from the fortymile herd. The cameras have helped monitor feeding preferences of the herd and levels of insect harassment. Changing forage and increased insect harassment are projected effects of climate change, and are thought to be a factor in the general decline of caribou herds.
16 January 2025 | national park service
New Fortymile Caribou Hunt Quota
A news release from the Alaska department of Fish and Game announcing reduced hunting quotas in the Alaskan range of the Fortymile herd. The new quota if for bullls only and is set at animals for the 2024/25 hunting season. The reduction in allowed hunting levels is based on the Department's new estimate of the herd's size. The department did a photographic estimate of the herd size last summer, and based on that data has modeled a herd size of 28,000-34,000.
18 July 2024 | Alaska Department of Fish and Game
Board recommends against proposed mining road in central Yukon
A Yukon environmental review has recommended against the building of a road that is in the range of the Fortymile and Klaza caribou herd. Concerns about the impact of the road on the two herds were a factor in the board's recommendation. The recommendation now goes for decision by the Yukon government and the federal Department of Fisheries and Oceans.
3 January 2024 | cbc north
Commission releases new version of Dawson land use plan
A news story about the release of a draft land use plan to be managed by the Yukon and Trʼondëk Hwëchʼin First Nation governments. The draft plan includes withdrawing a corridor used by the Fortymile caribou herd from use for quartz mining. The plan covers just under 40 thousand saquare kilometres in the Dawson region.
13 September 2022 | cbc north
What caribou do, without you: Fortymile herd outfitted with cameras
A news story on the data obtained from video cameras attached to collared caribou with the Fortymile herd that migrates between Alaska and Yukon. Analysis of the video allows for estimates of what proportions of different foods the caribou are eating, and of how long they spend in different activities.
2 May 2022 | Yukon News
Caribou cams give insight into secret lives
A news story describing research conducted on the Fortymile caribou herd that involved fitting caribou with GPS collars that also incorporated video cameras. The cameras captured snapshots of what the caribou were feeding on, and other behaviours.
16 February 2022 | Alaska Native News
Genetic legacy of last glaciation influences reindeer's seasonal migrations
This news release is about a new study that cross referenced GPS tracked movements and genetics of caribou, and found genes thought to be associated with migratory behaviour. The genetic differences are thought to spring from a genetic division during the last ice age, when populations were physically separated by ice sheets. The study authors say this has implications for possible loss of migratory behaviours if genes are lost through shrinking populations.
11 February 2022 | Science Daily
Caribou populations are dwindling, and we’re in denial about it
An opinion piece from Yukon Conservation Society about the impacts of industrial development on caribou herds. It notes that caribou habitat in Yukon is relatively well-protected.
26 October 2021 | Yukon News
Yukon at a crossroads with Fortymile caribou herd
This longer news story talks about the past and future of the Fortymile herd, shared between Yukon and Alaska. If raises questions about land use, and also about what constitutes an appropriate or optimal size for a caribou herd.
7 October 2021 | The Narwhal
Privacy commissioner recommends release of caribou location data
This news article is about the release of old caribou location data in Yukon. The Yukon government had refused to release the data after a privacy request. Yukon's information and privacy commissioner says there is no reason for the government to withhold most of the location records requested.
20 May 2021 | Yukon News
The delicate art of stabilizing Yukon’s Fortymile caribou herd
A feature-length article on the new management plan for the Fortymile caribou herd in Yukon. The article talks about the role of hunting in managing the herd size, and the comanagement plans for the herd split between the Yukon government and the Tr’ondëk Hwëch’in First Nation.
21 December 2020 | The Narwhal
Agreement signed for Fortymile caribou herd management plan
A story about the signing of an agreement between the Tr’ondëk Hwëch’in First Nation and the Yukon government on a management plan for the Fortymile caribou herd. The herd has been increasing, and management includes an allowable harvest. According to Yukon's Environment Minister, the management plan has three main goals, "promote a robust, sustainable population that will maximize the herd’s use of habitats within historical Yukon ranges; provide a phased approach to implementing harvest, given the long history of no-harvest of this herd; and increase knowledge and use of the herd through education and engagement."
15 December 2020 | yukon news
First Nation raises alarm after Yukon opens caribou hunt without herd management plan
A news story about a disagreement over opening up harvest of the Forty Mile herd (shared between Alaska and Yukon). The Yukon government has opened up a limited hunt of the herd. A local First Nation (Tr’ondëk Hwëch’in) that uses the herd doesn't believe it should be open to hunting until a management plan is in place.
26 August 2020 | Aboriginal Peoples Television Network
Tr'ondëk Hwëch'in organizes community hunt of Fortymile caribou to bridge generation gap
Members of the Tr'ondëk Hwëch'in First Nation (Yukon) are hunting caribou in the Fortymile herd for the first time in twenty years. The Tr'ondëk Hwëch'in had voluntarily stopped hunting the caribou herd after its numbers dropped to a low of 6,500. The herd, that migrates between Yukon and Alaska is now estimated at 84,000.
13 July 2020 | CBC
Related resources
Shifting and expanding ranges of a sub-Arctic caribou herd and associated changes in vegetation
An open-access academic article that examines the impact of an increasing caribou herd (the Fortymile herd, share between Alaska and Yukon) on its forage resources. The study found that when the herd was increasing, key forage areas were depleted of favoured caribou forage items such as lichens and willow, and that this may have led to the herd's subsequent deline.
Ecological applications (2025)
Usage: Non-commercial with attribution Format: web
Barren-groundFortymileClimate changeNatural factorsDesignated Office Evaluation Report Casino-Rude Road Construction Project
This is a recommendation by a Yukon assessment organization that denies a proposal for a new mining road that would affect two caribou herds, the Fortymile and the Klaza. The recommendation for the road project to not be allowed to proceed was based on a determination that, "...the Project will result in, or is likely to result in significant adverse effects to Ungulates and Traditional Land Use than cannot be mitigated." The recommendation now goes to the Yukon Government and the federal Deprtment of Fisheries and Oceans for a decision.
There is no direct link to this 72-page report prepared by the Yukon Environmental and Socio-economic Assessment Board (YESAB). The report is titled "recommendation" and is found under the "documents" tab after following the link to the project on the YESAB site.
(2024)
Population genetics of caribou in the Alaska-Yukon border region: implications for designation of conservation units and small herd persistence
An academic paper giving results from the genetics of carious caribou herds near the Yukon/Alaska border, including the Fortymile herd. This is important for conservation purposes, as the paper notes, "Canada classified caribou Designatable Units (DUs) for conservation in 2011, but lacked the genetic data needed to assess herds in the central Yukon...".However, the study was unable to definitvely assign the Fortymile herd to the barrenground caribou 'designatable unit' finding that the herd shared genetics with some northern mountain caribou herds.
(2024)
Usage: Non-commercial with attribution Format: web
PorcupineBarren-groundFortymileRange managementManagementA taste of space: Remote animal observations and discrete-choice models provide new insights into foraging and density dynamics for a large subarctic herbivore
An academic paper describing results from anaylzing footage from cameras on caribou collars. The paper focuses on the sorts of food that caribou of the Fortymile herd are eating. This information is important in selecting conservation areas, and in understanding how caribou diets (and numbers) might change in response to climat change.
(2024)
Usage: Non-commercial with attribution Format: web
Barren-groundFortymileRange managementClimate changeHuman disturbanceFortymile Caribou Herd: Video footage from caribou collars
A 1:45 video compilation of video taken from collared caribou in the fortymile herd showing a variety of behaviors including foraging, birthing, and nursing.
Alaska NPS (2021)
Critical summer foraging tradeoffs in a subarctic ungulate
This 38-page academic paper looks at the summer diet of the Fortymile caribou herd that ranges between Yukon and Alaska. It uses video from collars on the animals to analyze what they're eating, and other behaviours such as avoiding insects. The video confirmed a sharp decline in eating when insects such as mosquitoes were more present, and also confirmed that lichen is an important component of the herd's diet, even in summer.
ecology and evolution (Wiley) (2021)
Usage: Non-commercial with attribution Format: web
Barren-groundFortymileRange managementClimate changeContaminants in Arctic Caribou Synopsis Report 2019-20
A 9 page synopsis report of the Arctic Caribou Contaminant Monitoring Program. The program covers several Arctic herds. It concludes, "Levels of most contaminants measured in caribou kidneys were not of concern toxicologically, although renal [kidney] mercury and cadmium concentrations may cause some concern for human health depending on the quantity of organs consumed. Yukon Health has advised restricting intake of kidney and liver from Yukon caribou, the recommended maximum varying depending on herd (e.g. a maximum of 25 Porcupine cariboukidneys/year). The health advisory confirms that heavy metals are very low in the meat (muscle) from caribouand this remains a healthy food choice. There have been no health advisories issued for caribou in NWT or Nunavut."
Northern contaminants program (2020)
Usage: Non-commercial with attribution Format: pdf
PorcupineBeverly and QaminirjuaqBarren-groundBathurstLorillardFortymilePeopleContaminantsTactical departures and strategic arrivals: Divergent effects of climate and weather on caribou spring migrations
A 2019 academic paper that looks at factors affecting caribou migration timing and speed. The paper concludes that later arrival at calving grounds might indicate that females are in worse condition, and that calving and calf survival rates might be lower.
(2019)
Usage: Attribution Format: web
PorcupineBeverly and QaminirjuaqBathurstBluenose WestBluenose EastCape BathurstFortymileClimate changeDemography of an increasing caribou herd with restricted wolf control: Caribou Demography and Wolves
A 2017 academic paper on the Fortymile herd focusing on wolf predation and the impact of overgrazing on herd size. The paper counters earlier opinions that wolf control (lethal and non-lethal) had a significant impact on the herd’s growth. Paper available on request.
(2017)
Forty Mile Caribou in the Dawson Region
A 30-page report from 2012 on the Yukon portion of the herd’s range. It includes discussion of the potential impacts of forest fires.
Yukon Department of Environment (2012)
Format: pdf
FortymileFACT SHEET: Fortymile Caribou Herd
A five-page undated fact sheet on the herd, concentrating on the Indigenous knowledge of the Tr’ondëk Hwëch’in First Nation
Tr'ondëk Hwëch'in Heritage Sites