Yellowstone in Winter

“The Scientists’ Day Out”

We spent an amazing morning with Kira Cassidy, a wolf biologist who works for the park. She showed us her office, which included an incredible amount of binders full of data on the park wolves, going all the way back to the reintroduction in 1995, and some pelts from wolves who have died over the years. She is a wealth of knowledge and answered our many questions about wolves. As educators, we wanted to know what information she would want us to share with our students. She said that the biggest takeaway from the wolf reintroduction project would be the lessons we have learned from the removal of the wolves from the park. Their removal was celebrated at the time as a good thing for the ecosystem. Years later, we realized how important apex predators are to the ecosystem, and began making efforts to correct our mistake. The wolf reintroduction is an amazing example of the power of habitat restoration and management.

So many years of data from so many wolf interactions was humbling to see in the Wolf Project offices.

Once we started driving, we encountered a crowd at the same place where we saw the Wapiti wolf pack yesterday, so we made a brief stop but only saw one and it was pretty far away. We continued on to Lamar Valley to look for a carcass that Kira suspected was there based on GPS data from the Junction Butte pack from about a week ago. We split up into 3 groups to cover more ground, and were able to find it—- SCORE! A bison carcass! Not much was left, but Kira gave us a glimpse of the scientific process the researchers use by letting us help to collect data on the carcass as they attempt to determine cause of death. We sawed the femur in half to collect a bone marrow sample, and then we extracted a tooth to take back to the lab for processing.

Jessica got to saw the femur in half to collect the marrow sample!

Everyone say “cheese”….so we can take a tooth sample!

On the drive back to Mammoth we saw one more wolf, a black likely from the Junction Butte pack. We also heard it give one low howl, which was amazing to experience. Today was also a great day for coyote, we saw close to 10 in various places.

After lunch we had a choice in our activities. Some of us went cross-country skiing, it was the first time for Vin and he got the hang of it pretty quickly! Melissa was in her element, we decided she was the alpha skier.

Randy shows off his cross-country skiing skills.

Another group went to the ‘Boiling River’ (actually the Gardner river, but this is the local name for the particular spot where hot water from a thermal feature runs into the cold river water). After a most scenic walk, we quickly disrobed in the snow and began the descent to the crystal clear water. Temperature reading from the infrared thermometer ranged from 127 degrees to 20 degrees.

Blaire uses the infrared thermometer to measure the temperature of the water we are about to enter.

Slipping and sliding on the algae covered stones we waded in to find just the right temperature. With frozen eyelashes, we reveled in the rich mineral waters as we reflected on our phenomenal experiences. Navigating the hot springs and the flow of the icy river waters we successfully exited for a quick return to the car. American Dipper songbirds greeted and congratulated our daring spirits as we made a quick run for the suburban. Driving back to Mammoth Springs for a quick rinse in the shower, we spotted numerous bighorn sheep.

There is nothing like soaking in the ‘Boiling River’!

Today has been full of adventure and new experiences. More importantly, we have continued to build strong bonds with our teammates. We are so excited to continue this journey together!



  • Isabelle

    4 years ago

    Gross! That must have been gross pulling out the tooth and gross picking up the leg!

    • Mommy, Ursula Valgus

      4 years ago

      Hi Isabelle! While the pictures may look gruesome, extracting the tooth and collecting the bone marrow sample from the carcass provides Kira and her colleagues the opportunity to learn more about this animal when the results return from the lab. Depending on the type of animal carcass Kira finds, she uses a checklist for specific data points that she collects in the field. It really was fascinating to join her this morning as she doing really cool work on the Wolf Project. Maybe you’d like to join her team when you’re a bit older!

  • Thomas

    4 years ago

    Does the Boiling River seem to have less aquatic life than what is typically seen in Yellowstone rivers?

  • Thomas

    4 years ago

    In The Boiling River did there seem to be less aquatic life than is typical for Yellowstone rivers?

  • Thomas LaMaster

    4 years ago

    In The Boiling River is there a noticeable difference in aquatic life compared to other rivers in Yellowstone?

    • Gretchen Miller

      4 years ago

      Hi Thomas! Most of the rivers in Yellowstone have at least some thermal input, so there is probably a lot of similarity in the aquatic life. Those that went to the Boiling River said they saw similar wildlife to the other rivers we visited.

  • Adam Phillips

    4 years ago

    Boiling/Gardner River seems like a very interesting place to study. Where does the water flow into the region from? Is the entire “body” of water heated throughout or does it flow into the region cool and is then heated up as it progresses through the riverbed? How far does the heated water reach before it goes back to “normal”? Or is the heated water only the result of runoff and has no initial starting point and is just a reservoir that empties into the river? In any case, how is the water heated? I wonder what the residence time is for the water or if the sedimentology of that particular portion of the river is different with regards to other similar water sources of varying temperatures?

    • Gretchen Miller

      4 years ago

      Hi Adam! That’s a lot of questions, we can certainly discuss more in class. The short answer is that the hot water comes from the geothermal activity (underground initially), and in this location the way it mixes with the cold water from the river (mostly surface runoff) means you can safely be in the water in some places.

  • Brodie

    4 years ago

    What was the reason them removing the wolves, and what did they start to notice to make them bring them back?

  • Maggie Bradley

    4 years ago

    When the wolves were introduced in 1995, did the wolves come from an area with a similar climate or did they have to adapt to the new conditions? If they were not used to the new climate, did the wolf population immediately struggle when introduced? Was it difficult for the wolves to find food?

  • Tynaisha Poland

    4 years ago

    when you used an infrared thermometer to measure the temperature of the water you guys entered what was the out comimg temperature. was the water cold beacuse it looks very cold from your surroundings!!!

  • Dylan Watkins

    4 years ago

    What kind of carcass is that and with the tooth and marrow sample what can you find out

  • Briley Rhodes

    4 years ago

    I noticed that the Bison carcass in the picture didn’t have many of its bones near it; do the wolves eat the bones of the prey, or do they just scatter them around?

  • Lyla Sherwood

    4 years ago

    What was the reasoning behind the removal of the wolves initially? Did the wolves threaten other animals, is that why they were worried about the ecosystem?

what do you think?

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