Meet Our Yellowstone Guides

We love Yellowstone!  All our Yellowstone guides have many years experience in assisting participants of every age and background in place-based, science-based learning in the world's first National Park. We are adept at helping you feel Yellowstone's essence, not just see it. Spend a day with us and you will leave with memories of an unrivaled experience and a deeper appreciation for living on a moving, breathing planet.

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Rhiana Peck
Naturalist Guide
Rhiana grew up adjacent to Yellowstone Park, where she thrived on being an active outdoors woman with the mountains and rivers of the Great Yellowstone Ecosystem as a backdrop.
For the past decade, she has studied and lived abroad in India and Turkey, earning a degree in Sociology and Anthropology from Earlham College in Indiana. Her interest in history and the human experience lends to sharing the unique story Yellowstone tells with visitors from around the world.
After relocating back to the northern edge of the park in 2020, Rhiana is excited for the opportunity to immerse herself in her home dirt, and share her voice connecting the human story to a wild landscape. Winter finds her driving a snowcoach in Yellowstone’s interior based at Old Faithful, interpreting the landscape for a wide variety of travelers. Summer finds her based in Gardiner with the Walking Shadow Ecology team, presenting the stories of Yellowstone through the lens of geology, wildlife, and the human connection.
Rhiana is a Certified Interpretive Guide (CIG) with the National Association for Interpretation (NAI) and is certified in Wilderness First Aid and CPR.
Ashea Mills, Yellowstone Naturalist Guide
Ashea Mills
Naturalist Guide

Ashea has spent twenty-five years exploring and sharing the Greater Yellowstone Ecosystem, helping people connect to a wild landscape and to themselves. After obtaining a degree in English Writing Arts and Theater, she found herself in Yellowstone, working seasonally and falling in love with one of the most dynamic landscapes on earth. She has led all ages and interests through the park as a Yellowstone guide, including children’s programming, driving snow coaches, skiing and hiking deep into the backcountry, geyser gazing and road-based wildlife watching.

She is a certified Leave No Trace Trainer and Wilderness First Responder. She lives in Gardiner, MT with her husband Mike, an ecologist, and young daughter. Immersing in Yellowstone's geology and the surrounding public lands on skis and foot is where they find nourishment.

Dr. Mike Tercek, Ecologist
Mike Tercek, PhD

Mike first visited Yellowstone with his parents in 1982,  and 2020 is his 30th consecutive year working in the park. His research projects have included rare (endemic) plants in Yellowstone's geothermal areas, trophic cascades (wolf - ungulate - willow interactions) on the northern range, adaptations of plants to high carbon dioxide environments, and various number-crunching / big data analyses. For the last 10 years, he has focused mostly on climate change and its effects on protected lands. He likes to dabble in repairing or modifying electronic equipment, especially for scientific data collection.  Most of his work is aimed at producing practical results that will improve land management decisions. Through his consulting company (, he works on a wide variety of ecological and climate-related projects throughout the western US. He also manages, a tool for land use managers across the country. His work provides our Yellowstone guides with the most up-to-date information on Yellowstone ecology and climate science.

Thank you for a most sincere, and now deeper, appreciation for the journey, wildlife, the living Earth, and what brings us home to ourselves.

Leon A.

trip participant

Moonset over Electric Peak in Yellowstone Park
Mike Rosekrans, Yellowstone Naturalist Guide
Mike Rosekrans, M.Ed.
Naturalist Guide
Mike has been leading trips and environmental education programs around the Western United States for over a decade. Growing up in the Great Lakes Region of the Upper Midwest, Mike took a keen interest in the natural world at a young age. He received his bachelors degree in outdoor recreation from Winona State University in Minnesota and promptly moved west to begin his career and pursue his passion of exploring and teaching in the mountains and forests of the Western United States. In 2016 Mike completed his graduate studies, earning an M.Ed from Western Washington University in Partnership with North Cascades Institute. While in graduate school Mike began developing an interest in the ecology and natural history of grizzly bears and upon graduation spent a summer season in Denali National Park before permanently moving to Yellowstone where he was able to realize his dream of teaching programs related to grizzly bear natural history while also developing and implementing curriculum-based youth programs within Yellowstone National Park. Mike is a passionate Yellowstone guide who hopes that in providing people with a more holistic view of the Yellowstone Ecosystem that people will be inspired to preserve, protect, and make sound decisions in preserving our natural world.
Tyrene Riedl, Yellowstone Naturalist Guide
Tyrene Riedl
Naturalist Guide

Tyrene Riedl is originally from Portland, Oregon but relocated to Montana in 2002. Since 2007, Tyrene has worked as a tour guide, fly-fishing guide & instructor, Interpretive Trainer and outdoor educator for the Yellowstone Forever Institute, Yellowstone Association Institute, and Xanterra Parks & Resorts. Her 14 years experience leading programs and tours in the Yellowstone ecosystem, allow her to share a well-crafted, in-depth array of content covering park wildlife, geology, natural, cultural, and park history, and past and current park management strategies through her work as a Yellowstone guide. Tyrene finds inspiration in guiding both new and seasoned park visitors to find a deep and personal connection to Yellowstone and all wild places.

Tyrene is a Certified Interpretive Trainer (CIT) and Certified Interpretive Guide (CIG) with the National Association for Interpretation (NAI), certified in Leave No Trace (LNT), Wilderness First Aid, and CPR/AED. She passionately believes that education has the power to inspire change, increase understanding of, and develop a voice for our wild places.

Virginia Miller, Yellowstone Naturalist Guide
Virginia Miller
Naturalist Guide

Virginia comes to work as one of our Yellowstone guides from a long history in outdoor education and the Girl Scouts. She first worked in the park in 2012, thinking it would be just a fun one- summer job. But after falling in love with the animals, Yellowstone's thermal features, and even the lodgepole pines, she never left! Virginia has worked for 8 years with the Yellowstone Association and Yellowstone Forever Institute as a Naturalist, working with families, teacher workshops, school groups and everyone in between. In the Girl Scouts, she has worked as a summer camp counselor and Leadership Director, and as an international volunteer and Leadership Seminar facilitator. Virginia is a Certified Interpretive Guide, a Leave No Trace Trainer, and a Wilderness First Responder. After the initial shock of her first -30° Yellowstone winter days, this California girl now thrives in the winter and lives for summer hikes and paddle trips. She uses her degree in theater to make science and the outdoors come alive for students of all ages!

Walking Shadow is a business devoted to advancing knowledge of Yellowstone National park through highly experienced guides.

Christine P.
trip participant

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