Strengthening the Yellowstone Ecosystem & Heritage Resources

a herd of bison walking near a steaming geyser
Bison group grazing in Lower Geyser Basin at sunset.

NPS / Jacob W. Frank

Yellowstone National Park has wide-ranging natural, cultural, and geologic resources. This strategic priority centers on taking the actions necessary to strengthen, preserve, and protect these many resources. The park is committed to being a world leader in promoting large landscape conservation, understanding and responding to the impacts of climate change, protecting resources from increasing visitor use, and maintaining a robust scientific and research capacity to inform resource-related decisions.

Learn about how Yellowstone is “Strengthening the Yellowstone Ecosystem and Heritage Resources” below.


Resource Conservation Efforts

a bison leaping out of a trailer onto Tribal land
Releasing Yellowstone bison at Fort Peck Indian Reservation through the Bison Conservation Transfer Program.

NPS / Jacob W. Frank


The protection and recovery of bison in Yellowstone is one of the great triumphs of American conservation, and efforts are ongoing to maintain a viable, wild, migratory population of our national mammal.

Bison Conservation Transfer Program
Yellowstone established the Bison Conservation Transfer Program in 2017 to identify brucellosis-free bison and transfer them to American Indian Tribes for release as an alternative to shipping to slaughter. The success of the program depends on effective partnerships with the Fort Peck Tribes, InterTribal Buffalo Council, State of Montana, Department of Agriculture (Veterinary Services), and various nonprofit organizations. The program was initially funded by federal and Tribal governments, but the park recently expanded the program with a combination of government and philanthropic dollars.

Bison Research
Yellowstone continues scientific research and data collection on bison grazing and grassland health. Bison grazing benefits grasslands in Yellowstone by diversifying the composition of plants, maintaining plant production, enhancing soil nutrient availability, and improving soil water holding capacity. These benefits will also help maintain the functional integrity of grasslands under a warming climate.

View more bison research, publications, and reports.

Yellowstone Bison Management Plan
In summer 2023, the park initiated an Environmental Impact Statement process to prepare a new Bison Management Plan that will incorporate new information and changed circumstances since the existing plan was approved in 2000.

Learn more about bison management in Yellowstone.

a park ranger inspecting a cougars teeth before its release
Collaring and examining a cougar.

NPS / Jacob W. Frank


Cougars (mountain lions) are recovered in Yellowstone and numbers are fluctuating naturally in a manner that does not threaten their long-term viability. A remote camera survey grid established in 2020 enabled a population estimate of 29 to 45 cougars in northern Yellowstone. Sixteen adult cougars have been fitted with GPS telemetry collars to monitor predation, habitat selection, multi-species interactions, and energetics. The collars also have built-in accelerometers which continuously measure body movement and activity patterns. Accelerometer data displays discrete behaviors such as resting, traveling, killing prey, and feeding, and measures caloric expenditures.

Learn more about cougars in Yellowstone.


There were 108 wolves in 10 packs in Yellowstone during December 2022, including seven breeding pairs. The 2021 Montana Legislature mandated a reduction in the number of wolves statewide, approved new harvest techniques, increased the harvest limit per individual, extended the harvest season, and eliminated the quotas from wolf management units adjacent to the park. The Montana Fish and Wildlife Commission adopted these regulations, and 19 wolves from the park were harvested in Montana during the following winter of 2021-2022, including most of the Phantom Lake pack and one-quarter of the Junction Butte pack. In response, the park worked with the commission to reestablish a quota of six wolves outside the northern boundary to prevent overharvest.

Learn more about wolf restoration in Yellowstone.

people walking through a river
Electroshocking nonnative fish species in Soda Butte Creek.

NPS / Jacob W. Frank

Native Fish

Yellowstone is continuing a major effort to restore native fish and create resiliency in populations threatened by nonnative species and climate warming. Native arctic grayling and cutthroat trout (Yellowstone, westslope) have been released into 196 stream miles and 293 lake acres after non-native fish were removed.

Learn more about Yellowstone’s Native Fish Conservation Program.

Grizzly Bears

In 2022, park staff coordinated with the U.S. Fish and Wildlife Service, Interagency Grizzly Bear Study Team, and other federal and state agencies to develop the Conservation Strategy for the Grizzly Bear in the Greater Yellowstone Ecosystem. The foundation of Yellowstone’s bear management program is to prevent bears from obtaining human food and garbage. The park has installed bear-proof food storage boxes in 72% of the park’s 1,907 campsites. The park is on schedule to complete the installation of bear boxes in every campsite in 2026.

Learn more about bear management in Yellowstone.


The park led efforts to recover common loons and trumpeter swans, including the installation of a nesting platform at Grebe Lake and the release of cygnets in partnership with the Ricketts Conservation Foundation, Wyoming Wetlands Society, and USFWS. Four cygnets fledged from Swan Lake in 2022, which was the first successful cygnet production on the lake since 1967. The park also continued collaborative studies of the food habits, movements, reproduction, and survival of Clark’s nutcrackers, golden eagles, and ravens in northern Yellowstone.

Learn more about birds in Yellowstone.

a park ranger measuring streamflow with a device while standing in a stream
Measuring stream flow with a stream gauge.

NPS / Jacob W. Frank


Yellowstone responded to the 2022 flood event in coordination with U.S. Geological Survey, NOAA-National Weather Service, and the U.S. Army Corps of Engineers to maintain streamgages, provide river forecast data to downstream communities, and initiate interagency agreements to secure critical infrastructure repairs and emergency response planning. Hydrology staff provided assessments of wastewater discharge flow rates in coordination with park facilities staff to ensure appropriate sizing of Mammoth emergency treatment facilities. The park also initiated the first study of swimming area water quality to ensure public health.

Learn more about Yellowstone hydrology.


During 2021-2022, crews delineated 274 wetlands between Canyon Junction and Alum Creek along the road corridor; surveyed and delineated 35 wetlands for emergency repairs on the North Entrance Road; and reverified wetlands along the road corridor between Norris and Golden Gate, which included proposed parking lots for Bunsen Peak, Sheepeater Cliffs, and Norris Geyser Basin and an expansion of Swan Lake Pit. Additionally, crews surveyed rare plants and reverified wetlands for the temporary Mammoth wastewater treatment plant, surveyed two areas in Bechler in support of trail projects, and surveyed the Gardner River High Bridge area for impact on wetlands.

Learn more about wetlands in Yellowstone.

park rangers using equipment to map a nearby thermal feature
Using photogrammetry to create a 3D model of Cistern Spring after a Steamboat Geyser eruption.

NPS / Jacob W. Frank


In 2020, Yellowstone partnered with the USGS 3D Elevation Program to acquire LiDAR data of the entire park. The park again acquired LiDAR of terrain affected by the 2022 flood event through the USGS Geospatial Products and Services Contracts program. Comparative analyses of the 2020 and 2022 post-flood LiDAR data will inform park managers of landform changes in the park’s flood-affected areas.

The Geology Program worked with the NPS Geologic Resources Division to engage the Department of Earth Sciences at Montana State University to identify and begin remapping the geologic maps that cover the extent of the park. Yellowstone lacks an accurate and complete geologic map, and accurate and detailed geologic maps are integral to understanding the terrain on which infrastructure is placed in our national parks.

The Geology Program plans to publish a 1:100,000 scale geologic map of the park and create a 1:62,500 scale geodatabase for online use. They installed and is testing a telemetered data logger system at thermal features in the Upper Geyser Basin (Old Faithful). Each logger station consists of a temperature sensor that is placed in a geyser runoff channel and an electronic logger that sends thermal data to a receiver that is connected to the internet. These data are used to monitor seasonal and other changes in geyser activity, analyze changes in geyser activity with other large datasets, and allow for better predictions on geyser activity.

Learn more about Yellowstone geology.

a park ranger looking at the underside of a piece of bark from a tree
Monitoring evidence of mountain pine beetle infestations under whitebark pine tree bark.

NPS / Jacob W. Frank

Whitebark Pine

In December 2022, whitepark pine was listed as threatened under the Endangered Species Act. Yellowstone started a project to assess whitebark pine health in six core areas in 2021. In 2022, the project went full-scale when staff measured the health across 525 acres of the park. Overall, 11% of whitebark pine trees had evidence of blister rust infection with two stands comprising the highest percentage of infected trees. Fifteen trees were observed with evidence of recent mountain pine beetle attack. The park continued these health assessments of the core areas in 2023.

The park also developed, in partnership with USFWS, an innovative approach for surveying whitebark pine. The USFWS shared this model with other federal agencies as the standard practice of monitoring whitebark pine into the future.

Learn more about forests in Yellowstone.

Science Communications

Yellowstone designed and published annual reports for the wolf, bear, bird, and native fisheries programs in 2021-2022. View these science publications and reports.

The Grazing Issue of Yellowstone Science was a central focus and it includes crucial information about ongoing research to understand the effect that ungulates have on the northern range of the park.

View published issues of Yellowstone Science at:

construction vehicles building a brand-new road through a mountainous area
Improving the Old Gardiner Road (now known as the North Entrance Road) after the 2022 flood event destroyed access between Mammoth Hot Springs and the North Entrance in Gardiner, Montana.

NPS / Jacob W. Frank

Planning and Compliance

In 2022, the Planning and Compliance team completed over 120 natural and cultural resource compliance requests parkwide, which included the temporary Mammoth wastewater treatment plant, obsolete housing replacement, Fort Yellowstone rehabilitation, and numerous telecommunication projects.

The team initiated and continued planning efforts for the Laurel Dormitory replacement, Canyon employee housing rehabilitation, parkwide water and wastewater treatment plant upgrades, the North and Northeast entrance road replacements, and bison management plan.

The team issued 139 research permits and continued frontcountry monitoring efforts at five focal locations and produced regular reports on visitor use patterns used to inform and support parkwide managed access systems and visitation-based decision making in response to the 2022 flood event.

Additionally, the team completed two emergency compliance Decision Memos for response to the 2022 flood event. The park received approval from the Department of the Interior and the Office of Environmental Policy and Compliance for the Decision Memorandum and Environmental Review to support emergency activities for improvements to the Old Gardiner Road and Northeast Entrance Road. Both documents approved and facilitated timely emergency repair of damaged sections of roadway to allow access to and from communities isolated by the flood.

Learn more about flood recovery and operations in Yellowstone.

a person lifted up in a large crane trimming trees
Trimming trees in Fort Yellowstone.

NPS / Jacob W. Frank

Historic Structures and Cultural Landscapes

Through the Great American Outdoors Act Legacy Restoration Fund, the park received funding to rehabilitate historic Fort Yellowstone, historic Laurel Dorm, and part of the Old Faithful Historic District. The Fort Yellowstone Rehabilitation is one of the largest historic preservation projects in the NPS. The team also completed emergency natural and cultural resource compliance actions in consultation with the Montana and Wyoming State Historic Preservation Offices and the Advisory Council on Historic Preservation to facilitate emergency actions in response to the 2022 flood event. The team evaluated 128 undertakings, completed 14 determinations of eligibility, and completed 17 full consultation processes with Montana and Wyoming State Historic Preservation Offices, ensuring compliance with Section 106 of the National Historic Preservation Act


In 2022, the archeology program performed 61 site condition assessments throughout the park.

Learn more about archeological resources in Yellowstone.

Heritage and Research Center

In 2022, the team catalogued an additional 180,053 items, responded to 514 internal and 1,762 external research requests, and managed 58 total outgoing loans with 621 items on exhibit at the National Museum of Wildlife Art in Jackson, Wyoming, and to the DOI Museum in Washington, D.C. Park concessioner, Xanterra Parks and Resorts, transferred nearly 6,000 historic maps and architectural drawings of concession-managed structures. The team also re-articulated wolf skeleton 302M with the help of Yellowstone Forever. The wolf skull collections were 3D-scanned and available at

Learn more about the Heritage and Research Center.

Sustainability Efforts

an electric vehicle being charged
Charging an electric government vehicle.

NPS / Jacob W. Frank

Municipal Waste Program Analysis

In 2022, consultants, concession partners, stakeholders, and NPS staff worked together to analyze the park’s municipal waste program and provide recommendations for improvement focused on three main goals: 1) increase diversion from the landfill, 2) reduce greenhouse gas emissions, and 3) reduce costs.

Propane Pickup

In 2022, Worthington, a propane canister manufacturer, was awarded a contract at their expense to remove a stockpile of 16,508 propane canisters, saving Yellowstone over $80,000.

Recycling Bins

In 2022, the National Park Foundation awarded the park grants from Tupperware and Coca-Cola to purchase new and replace 129 recycling bins throughout the park.

Electric Vehicle Charging

In 2022, the park assessed its fleet replacement opportunities over the next five years and completed a field assessment through a partnership with the National Renewable Energy Lab and the Federal Energy Management Program. The assessment identified 42 locations for potential electric vehicle changing stations and the need for service panels, trenching, and a new transformer.

a person replacing light bulbs in a ceiling
Installing new LED bulbs in an NPS building.

NPS / Jacob W. Frank

Light Bulb Upgrades

With support from Yellowstone Forever, the park continues its effort to convert over 35,000 light bulbs to LEDs. The new lights require only half the amount of electricity compared to fluorescent and incandescent bulbs. They have also installed vacancy sensors in many office spaces to automatically turn these lights off when not in use.

Building Upgrades

To ensure better historic preservation energy conservation, the park is upgrading many aspects of historic structures including installing vapor barriers, wall and ceiling insulation, double pane storm windows, weatherstripping and air sealing, and rehabilitating exterior doors. This work is often accomplished with partners, through various agreements and contracting methods.

Sustainability Reports

Yellowstone staff coordinate the collection of data for energy, water and fuel use and waste operations from NPS and concession partners and compile it in an annual report.

Solar Power

In early 2022, the park installed a 45kW ground mounted photovoltaic system in partnership with Northwestern Energy to provide the remote, off-grid Bechler Ranger Station with renewable electricity. The backup propane generator was unused during the new system’s first summer online.


Threats to the Yellowstone Ecosystem

At 3,437.5 square miles, Yellowstone National Park forms the core of the Greater Yellowstone Ecosystem - one of the largest, nearly intact, temperate-zone ecosystems on Earth. To protect this ecosystem from an increasing number of threats, continuous planning and adaptations are needed into the foreseeable future.

a person downloading data from a climate monitoring site
Downloading data from a climate monitoring site.

NPS / Jacob W. Frank

Climate Change

Park staff and partners are working on tools to better predict near-term weather events and dangerous conditions. Near-term threats include an increased chance of rain on snow causing flood events that impact infrastructure; low summer flows combined with warmer stream temperatures impacting native, cold-water fish and recreational fishing opportunities; rapid increase in the spread of invasive grasses impacting native vegetation; shrinking wetland resources impacting amphibians and other vulnerable wildlife; a reduction in whitebark pine impacting alpine ecosystems; and extreme wildfire behavior impacting forest vegetation, park infrastructure, and visitor health and safety.

The best chance of avoiding catastrophic damage to Yellowstone ecosystems is to anticipate the most likely future conditions, identify what is vulnerable under those conditions, and on a case-by-case basis, make intentional decisions about whether we should resist, accept, or direct the change. Using this structured decision-making process, the park has begun working on climate-informed adaptation plans for aquatic resources, park infrastructure, vegetation management, and wildlife management.

To better understand species response to climate change, Yellowstone is studying insect species with different physiologies, behaviors, and seasonal timing. The research occurs along a 4,500-foot elevational gradient at seven long-term ecological monitoring sites in the northern section of the park. Equipment at each site continuously monitors weather, soil conditions, the soundscape, snowpack, and plant phenology. The data generated will provide critical information for focal species and inform larger trends that may be incorporated into climate adaptation response planning.

Learn more about how climate change is impacting Yellowstone.

a person carrying a sprayer backpack to spray invasive plants
Spraying for invasive weeds near the Madison River.

NPS / Jacob W. Frank

Terrestrial Invasive Species

Invasive nonnative plants can displace native plant species, including some endemic to the park’s geothermal habitats, change the integrity of vegetation communities, increase fire frequency, and affect the distribution, foraging activity, and abundance of wildlife. In 2021-2022, crews inventoried 18,440 acres of invasive plants, a 25% increase from the last reporting period. Crews treated 103 infested acres with herbicide and manually pulled 3 acres. To date, crews have mapped 189 acres of cheatgrass in the park mostly around park construction projects, thermal areas often used by wildlife, and routinely disturbed visitor use areas and backcountry camp sites. In 2021-2022, crews herbicide-treated 113 priority acres to prevent these patches from spreading into uninvaded and otherwise intact plant communities. In 2021, the park started working with various researchers, the U.S. Forest Service, and USGS, to develop remote sensing tools aimed at predicting the occurrence of small, isolated patches of cheatgrass and other invasive annual grasses to target them for aggressive treatment and revegetation.

Learn more about invasive plants in Yellowstone.

Wildlife Health

In 2022, the program coordinated the collection of 190 samples from 53 waterbodies across the park for the early detection of high-priority aquatic invasive species. Field crews collected 43 swab and tissue samples from captured amphibians at six sites for the presence of disease agents (chytrid fungus, ranavirus). Bat monitoring continues to be important as white-nose syndrome has spread into western Wyoming near the park’s eastern boundary. The program deployed 32 acoustic point stations across the park. This monitoring effort has yielded hundreds of thousands of bat calls that will be used to identify white-nose syndrome impacts on bat populations. Additionally, eight winter acoustic monitoring stations were deployed across northern Yellowstone to monitor bat activity.

a person washing the propeller on a boat
Flushing a boat engine during an aquatic invasive species inspection.

NPS / Jacob W. Frank

Aquatic Invasive Species

In 2022, Yellowstone staff conducted 2,975 watercraft inspections with 1,049 high-risk inspections and 210 decontaminations compared to 2021, which had 3,878 inspections with 134 high-risk inspections and one decontamination. In 2021, the AIS Program started using the “Colorado” watercraft inspection database. This database is used by other organizations throughout the West to collect and share inspection data and is key to communicating with partners about risks. In 2022, Yellowstone collected 190 samples as part of a new, eDNA-based aquatic invasive species early detection monitoring to allow for rapid response in the event of a new AIS detection.

Nonnative Lake Trout Suppression

Since 1995, more than 4.5 million lake trout have been removed by suppression efforts on Yellowstone Lake. Over the past decade, reproductive lake trout (age 6 and older) have been reduced by more than 80%.

Learn more about nonnative fish species in Yellowstone.

Increased Visitation

Visitation has increased substantially over the past decades. Although most visitor impacts occur within the road corridor and developed areas, equating to less than 7% of the park, Yellowstone is developing a new visitor use management strategy that focuses heavily on better understanding and responding to visitor impacts on resources across the park. The park’s strategy focuses on visitor impacts to 1) park resources, 2) park staffing, operations, and infrastructure, 3) visitor experience, and 4) gateway communities.

Learn more about visitor use management in Yellowstone.


More Information

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Discover the natural wonder of Yellowstone, from the geology beneath the plant communities to the animals migrating through the ecosystem.

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Science & Research

Explore the endeavors that enhance our knowledge of the region and inform preservation decisions.

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History & Culture

Explore the rich human and ecological stories that continue to unfold.

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Resources & Issues

Review or download your copy of the handbook that compiles a large amount of park information.

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Yellowstone Science

Yellowstone Science shares in-depth, science-based knowledge about the Greater Yellowstone Ecosystem.


Yellowstone "Resources" News

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    Other Strategic Priorities

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    Focusing on the CORE

    Learn how Yellowstone is improving working and living conditions, managing finances, and improving operating frameworks.

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    Delivering a World-Class EXPERIENCE

    Learn how Yellowstone is providing a high-quality visitor experience for millions who visit yearly while ensuring resources are protected.

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    Investing in INFRASTRUCTURE

    Learn how Yellowstone is addressing deferred maintenance, improving asset conditions, and protecting investments.

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    Building Coalitions & PARTNERSHIPS

    Learn how Yellowstone is building and aligning priorities with many partners, including Tribes, elected officials, nonprofits, and more.

    Last updated: April 29, 2024

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