Wolves Return to Yellowstone

How did decision-makers create and choose a plan for reintroducing wolves into Yellowstone National Park?   


How are decisions made when there are so many different perspectives about bringing wolves back into an ecosystem? Let’s explore the contentious debate that guided the 1994 decision to reintroduce wolves into Yellowstone National Park. This page will guide you through a simulation of the actual decision-making process and public meeting led by the US Fish and Wildlife Service (USFWS). 

The goal of the public meeting is to answer this question: 

How can wolves be reintroduced into Yellowstone to coexist and have minimal conflict with people?

To recreate a public meeting, you’ll need to set aside your personal perspective and take on another citizen’s role. Each citizen will present a statement that represents and defends his or her position on the reintroduction. All participants will be asked to respectfully consider these diverse perspectives, comment on the proposed reintroduction scenarios, and consider ways to compromise on a plan that’s best for both citizens and wolves. After the public meeting simulation, you will change hats to take on the role of a USFWS employee. In teams, you will weigh citizen input and decide on the best plan for reintroducing wolves into Yellowstone National Park. 


Original lesson resource: Activities on this page are adapted from Wolves of Yellowstone Teacher Guide, a free curriculum developed by PBS Learning Media and The Nature Conservancy that you can download. Refer to p. 12-20 for the activities on this page.


 Identify Yellowstone’s Ecosystem Services

How might a healthy ecosystem with wolves benefit people? 

Ecosystem services are the many benefits that an ecosystem provides to people and society, and can be affected by the health of that ecosystem. Benefits could include clean water and air, crop pollination, nutritious food, nutrient-rich soil, and erosion protection. Ecosystems can also provide recreational, cultural, and spiritual benefits.

  1. Learn more about the four types of ecosystem services here:
  2. Make a class list of ecosystem services that a healthy Yellowstone ecosystem could provide for people. This might be helpful to your citizen and to the USFWS decision-makers.

Note: If you want to become more familiar with Yellowstone National Park, watch this video: Plan Your Visit from The National Park Service.


 Prepare for a public meeting simulation

The goal of the public meeting is to answer this question: How can wolves be reintroduced into Yellowstone to coexist and have minimal conflict with people? You will prepare to represent the perspective of a citizen, or of a USFWS employee decision-maker.


Participate in the public meeting simulation.

Meeting topic: How can wolves be reintroduced into Yellowstone so they can coexist peacefully with people with minimal conflict?

Agenda: Citizens will present their position statements at this public meeting. Then USFWS employees will meet to decide on a reintroduction scenario that takes the different perspectives into account. 

Citizens present position statements 

  1. Choose one or two USFWS employees to moderate the citizen presentations, using the procedure described in the prompt card. 
  2. Form a double circle with the inner being the 12 citizens who will give statements, and the outer being the USFWS employees who will be listening to gather information to help them decide on a reintroduction scenario.
  3. The USFWS moderator(s) will begin and facilitate the meeting by following the Prompt Card. Consider having one USFWS employee to be a timekeeper to alert students when they have talked for their allotted time.
  4. It is critical for USFWS employees to silently take notes on the citizen presentations because you will need this information when it is time to discuss the different reintroduction scenarios. You will also be able to ask questions after all citizens have presented.

USFWS employees debate the reintroduction scenarios

  1. When the public meeting is over, switch circles. Now the USFWS employees form the inner circle, with the citizens watching and taking notes. 
  2. Consider choosing a different moderator for this discussion. The moderator’s job is to make sure everyone has a chance to speak and be heard. Everyone will be completing the Wolf Reintroduction Scenario Matrix as a group.  
  3. USFWS employees: Review your notes and be ready to discuss which scenario option seems best, considering the views of the public and the desire to maintain ecosystem services for people (e.g., clean air and water, nutrient cycling, prevention of soil erosion, recreational opportunities, ecotourism, etc.) while also maintaining biodiversity in the park. 
  4. Moderator: Guide the discussion and make sure the information is recorded on the Scenario Matrix. For each scenario, ask for information about which ecosystem services are promoted, and any possible design constraints. These could be social, scientific, and economic limitations.
  5. Modifications to the scenarios can be made to deal with possible constraints or to support ecosystem services.
  6. Citizens: You are silently listening to the USFWS discussion, taking notes about the scenarios and any proposed modifications on your copy of the Scenarios Matrix.


USFWS employees decide on a scenario

  1. Once all scenarios have been discussed and compared, the USFWS employees will choose and propose a scenario to the public citizens, explaining their supporting reasons and any modifications.
  2. Citizens, you now can share any concerns or ideas you have about the proposed scenario. Moderators, you are in charge of calling on people to speak, and keeping respectful order in any discussion.
  3. After any citizen questions and concerns are addressed, the USFWS employees have the final say in the scenario proposed.

Reflect on the Public Meeting

  1. How did the role you represented compare with your personal views?
  2. What did you learn about yourself during the public meeting simulation?
  3. How did participating in the public meeting affect your personal views on wolves?
  4. My favorite part was ____.
  5. My best work was ____.
  6. If I could do this again, I would try to improve by ____.
  7. If I could do this again, I would change ____ about the simulation. 
  8. What else do you want the teacher to know about your preparation and participation in the meeting?

Impact of the Yellowstone Decision

The reintroduction scenario that was ultimately selected was #1, with a few modifications based on public comments. What were the impacts of this decision?

  1. Read this press release. (Final Environmental Impact Statement. Completed, May 4, 1994)
  2. Watch the full video of Wolves of Yellowstone | EARTH A New Wild. Watch the second half (2:39 - end) several times to catch all the ecosystem connections described.
    • How have wolves impacted ecosystem services in Yellowstone?
    • How have wolves affected the local economy?

What has happened to other living organisms and nonliving parts of the ecosystem after reintroducing wolves? Create a second bubble concept map that shows these changes in the ecosystem. Start with a central bubble of “Wolves Reintroduced.” You can use this handout to record your answers.


Trophic Cascade – It’s Complicated!

Which ecosystem changes are because of the wolves’ return?

This video went viral when released, and has helped the public understand the significant impact an animal like the wolf can have on its ecosystem. Scientists continue to research trophic cascade effects, looking at which ecosystem changes are directly caused by the wolves’ return.

  1. Watch the video with a critical lens for accuracy based on what you’ve learned on this Quest.
  2. Click on the button "Scientists Debate: Do Wolves Change Rivers?" and read about the current research on the relationship between Yellowstone's wolves and a trophic cascade. 
  3. Complete the Points to Ponder.

20 Years After the Yellowstone Reintroduction 

What really happened compared to what people thought would happen?

More than twenty years have passed since the reintroduction of the gray wolf into Yellowstone in 1995. Much scientific research continues to investigate their impact on the ecosystem and people. What are you curious about? Read articles on different impacts to find out what’s actually happened.

  1. Divide into seven Wolf Reintroduction Research Teams.
  2. Gather and summarize information about your topic. You can:
    • Read articles on your topic listed below,
    • Read articles listed in “More Articles: Latest Research in Yellowstone,” 
    • Do an internet search for other relevant writings or videos. Jot down the publisher, purpose of the article, the message the author wants to give the reader, etc. 
  3. Prepare to present to other teams at a simulated Wolf Conference. The presentations can be in any multimedia (visual and written) format.
  4. Be sure to take notes on other presentations. They will be helpful for you later in the Quest.
educator note

Driving Question: How did decision-makers create and choose a plan for reintroducing wolves into Yellowstone National Park?

 What we do on this page: 

  1. Prepare for a simulated public meeting on reintroducing wolves into Yellowstone National Park. Each student will research and take on the role of a citizen or an employee of the US Fish and Wildlife Service.
  2. Participate in the public meeting by presenting and listening to others.
  3. Weigh the pros/cons for different reintroduction scenarios and decide which should be implemented.
  4. Review and discuss data on the impact of wolves in Yellowstone 20 years after their reintroduction, including research on trophic cascade effects.

What we figure out:  

  1. A public forum provides a way for decision-makers to hear different perspectives of citizens, to address misperceptions, and share scientific facts.
  2. Citizens have diverse and polarized perspectives.
  3. Hearing others’ perspectives in a respectfully-run meeting builds understanding and empathy.
  4. US Fish and Wildlife gathered input from Wyoming citizens when making a decision about how to reintroduce wolves into Yellowstone.
  5. Some anticipated effects of wolves in Yellowstone before reintroduction differed from what scientific research shows has happened 20 years later.
  6. The impact of wolves in Yellowstone has been positive for the ecosystem, though the growing body of scientific research is not in agreement that wolves are the only cause of a trophic cascade.

Additional resources and ideas: 

Original lesson resource: Activities on this page are adapted from Wolves of Yellowstone Teacher Guide, a free curriculum developed by PBS Learning Media and The Nature Conservancy that you can download. Refer to p. 12-20 for the activities on this page.

  1. The original lesson plan for the public forum simulation is described on p. 12-18 and called Part 2: Evaluate Solutions for Maintaining Ecosystem Services and Biodiversity The Student Role-Playing Materials — Scenarios Matrix can be found here
  2. The original reference for guiding the public meeting is on page 15-16, #9-21, and can be used as a reference.
  3. 20 Years After Wolf Reintroduction to Yellowstone is on p. 19-20. The instructions for comparing the impacts of Yellowstone wolves on the ecosystem and people twenty years after reintroduction are adapted from the lesson on these pages. Team 7 has been added to address the new research on trophic cascades, additional current articles have been added.
  4. Trophic cascade: To understand trophic cascades more deeply, students can revisit other sections on the topic found on this page and the previous page–“Yellowstone Without Wolves” – and review the scientific evidence and debate around the effects of wolf reintroduction on a trophic cascade. The summary of the more recent scientific evidence is repeated in this section.

Scientists Debate: Do Wolves Change Rivers? 

It is widely agreed that taking wolves out of their ecosystems has caused a host of negative effects. The primary effect of wolf elimination was an increase in elk and deer populations that led to overgrazing of woody trees like willow and aspen. This led to a reduction in beaver populations and degradation of rivers and riparian habitat. The animals that depended on these rivers, like birds and fish, were then affected negatively as well.  When wolves were reintroduced in Yellowstone, scientists identified positive effects like the restoration of woody tree species, gradual increases in beaver populations, and the improved health of rivers. However, the debate is about whether or not wolves were the sole driver of this restoration¹ ² ³. Research has uncovered other factors that also seem to be contributing to the positive shift⁴ ⁵. Water availability, effects of wolves on other predators, and human hunting all have been shown to have an effect on elk populations, and require further investigation⁶.  This is an important reminder that interactions among wolves, their prey, and the ecosystems’ vegetation are complex.  The common ground shared between both sides of this scientific debate is that the accurate story is way more complicated than the trophic cascade’s top-down, wolves-causing-ecosystem-rebalance-all-by-themselves explanation. In the field of ecology, each organism in an ecosystem plays a unique role. When one organism is removed, the rest of the ecosystem can be affected. If people help an organism return, the goal is not to restore the ecosystem to what it used to be, but to try to help improve or maintain the health of the ecosystem as it is now. The case study of Yellowstone suggests that restoring wolves to the landscape can help restore balance. It also indicates that more research needs to be done.  Even if their role as a main driver of the trophic cascade is debated, scientists agree that wolves are important to the ecosystem, and that bringing them back could push the ecosystem further towards a healthier balance.