What Fish Are in Yellowstone? Exploring the Waters of Montana

Yellowstone National Park, with its vast wilderness, geothermal wonders, and iconic landscapes, is not only a place of beauty but also a haven for a variety of wildlife. Beneath the park's shimmering lakes and flowing rivers, the waters teem with life, including a wide array of fish species. However, just like the geological features of the park, the waters have their own set of challenges—especially when it comes to invasive species.

As we explore what fish are found in Yellowstone, it’s important to also highlight the fish that don’t belong, as these invaders threaten the balance of the park's delicate aquatic ecosystems.

Native Fish in Yellowstone

Yellowstone’s aquatic environments have been home to a range of native fish species for centuries. These species are well-adapted to the park’s high-altitude, cold, and fast-moving waters. Some of the notable native fish species include:

1. Yellowstone Cutthroat Trout

   The Yellowstone Cutthroat Trout (Oncorhynchus clarkii bouvieri) is one of the most iconic fish species in the park. Known for its vibrant red or orange markings on the underside of its jaw, this trout is a vital part of the ecosystem. It serves as food for many animals, including birds of prey, bears, and larger fish. Historically, the Yellowstone Cutthroat Trout has been the dominant fish species in the park’s rivers and lakes.

2. Montana (Westslope) Cutthroat Trout

   Found in some of the park’s streams, these trout are native to the Rocky Mountains and are closely related to the Yellowstone Cutthroat. They can be found in a variety of habitats, from mountain streams to large rivers.

3. Mountain Whitefish

   Mountain Whitefish (Prosopium williamsoni) thrive in the clear, cold waters of Yellowstone's rivers. These fish are typically found in the slower-moving sections of the rivers and are often overlooked in favor of more famous species like the trout. However, they play an important role in the food web and are an important prey species for larger fish.

4. Arctic Grayling

   Arctic Grayling (Thymallus arcticus) are another native fish species found in Yellowstone’s colder waters. Their long dorsal fin and vibrant colors make them an easily recognizable species. While historically abundant, their populations have dwindled in some areas of the park due to habitat degradation and competition from invasive species.

   
   
   
   

Invasive Fish Species in Yellowstone

While the native fish of Yellowstone are important to the ecosystem, several invasive species have been introduced to the park’s waters over the years, often by humans. These non-native fish threaten to displace the native species and alter the delicate balance of the aquatic environment. Here are some of the invasive species causing concern:

1. Rainbow Trout

   One of the most well-known invasive species in Yellowstone is the Rainbow Trout (Oncorhynchus mykiss). Originally from the Pacific Ocean basin, this trout has been stocked in many rivers and lakes across the park. The Rainbow Trout is more aggressive and adaptable than the native Yellowstone Cutthroat Trout, which has led to hybridization between the two species. As a result, the genetic integrity of the Yellowstone Cutthroat Trout is at risk. Rainbow Trout also compete for food and space with native fish species, disrupting the local ecosystem.

2. Lake Trout

   Lake Trout (Salvelinus namaycush) are another invasive species that have caused significant harm to Yellowstone’s aquatic ecosystems. They were first introduced into Yellowstone Lake in the early 20th century, likely by anglers seeking to catch larger fish. Unfortunately, Lake Trout are voracious predators, and their presence has led to a steep decline in native Yellowstone Cutthroat Trout populations. Lake Trout consume large numbers of Cutthroat Trout eggs and young fish, preventing the species from reproducing successfully. As a result, the Yellowstone Cutthroat Trout population has been severely impacted, which also affects the predators that rely on them, such as bears and eagles.

3. Brook Trout

   The Brook Trout (Salvelinus fontinalis), native to eastern North America, is another invasive species that has found its way into the park’s rivers and lakes. Brook Trout are opportunistic feeders and can outcompete native fish for food resources. They also prey on smaller fish, which puts pressure on the populations of native species like the Yellowstone Cutthroat Trout.

4. Brown Trout

   Brown Trout (Salmo trutta), another non-native species, were introduced to Yellowstone in the late 1800s. While Brown Trout do not have as direct an impact on the Yellowstone Cutthroat Trout as the Lake and Rainbow Trout, they still compete for food and space. They are also known to hybridize with native species, further complicating the issue of maintaining the genetic integrity of Yellowstone’s fish populations.

The Struggle to Protect Yellowstone’s Native Fish

The presence of invasive species in Yellowstone’s waters presents a significant challenge for park officials and conservationists. Efforts are being made to manage and control invasive fish populations through various means, such as:

• Targeted Fishing Programs

  In some cases, park officials allow anglers to target invasive species, particularly Lake Trout, in an effort to reduce their numbers. These programs are closely regulated to ensure that fishing practices are sustainable and do not negatively impact the park’s ecosystem.

• Habitat Restoration

  Efforts are underway to restore habitats for native fish species, such as the Yellowstone Cutthroat Trout. This includes improving water quality, protecting spawning grounds, and eliminating barriers to fish migration.

• Education and Awareness

  One of the key ways to prevent the spread of invasive species is by educating visitors about the importance of cleaning their gear and following park guidelines to prevent the introduction of non-native species.

  
  

  

  
  

Discover Yellowstone’s Waters with Old Faithful and Friends

If you’re looking to experience the stunning beauty of Yellowstone’s waters and the rich diversity of fish species, why not take a guided tour with Old Faithful and Friends Shuttles and Tours? Our experienced guides will not only show you the park’s iconic landmarks, but also give you an in-depth look at the fascinating world of Yellowstone’s aquatic life, including information on both native and invasive species.

We offer a range of shuttle services and tours tailored to fit your needs, whether you're looking for a relaxing day exploring the park or an in-depth, educational experience. From the majestic waters of Yellowstone Lake to the crystal-clear rivers that wind through the park, we’re here to ensure that you get the most out of your visit.

For more information or to book your next adventure, give us a call at 406-600-8408 or email us at info@oldfaithfulandfriends.com.

Conclusion

Yellowstone National Park’s waters are home to a rich and diverse array of fish, but they are under constant threat from invasive species. While native species like the Yellowstone Cutthroat Trout are vital to the health of the park’s ecosystem, the introduction of non-native fish has disrupted the balance of these aquatic environments. It’s up to all of us—anglers, visitors, and conservationists alike—to play a part in protecting these iconic species and ensuring the future of Yellowstone’s freshwater habitats. Whether you’re casting a line, enjoying the beauty of the park, or taking a guided tour with Old Faithful and Friends, remember the delicate balance of life that thrives beneath the surface of Yellowstone’s pristine waters.