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The Team

Who We Are

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John Ackerman

Founder & CEO

John Ackerman lives in the Farmington-Lakeville area and has been exploring caves since he can remember. He is credited with discovering over 50 caves in Southeastern Minnesota. John established the Minnesota Cave Preserve in 1989 to perpetually preserve, study, protect and to promote conscientious exploration and conservation of our unique underground wilderness. The preserve owns seven properties in Southeast Minnesota and Northern Iowa, which provides access to 36 miles of cave passages. The properties encompass 45 caves, 724.4 surface acres and 1,300 additional acres of subterranean rights. John is the founder of the MN Caving Club and together with club members, can be found most weekends in Fillmore County, searching for another amazing find.

Emily Hudson


Emily Hudson lives in St. Paul, Minnesota and is a 3rd generation caver. She is extremely passionate about doing project caving, including digging in tiny spaces, exploring and surveying new passages. She also enjoys seeing the smile on her son’s face when he comes caving with her! She recently graduated with her master’s in psychology from Walden University and works with people to help them find jobs that fit their skills and interests. She has been caving since she was seven years old and was appointed as a board member for the Minnesota Caving Club in 2013. She has attended several NSS-sanctioned cave rescue trainings. When she is not caving, she can be found doing light acrobatics, kayaking, dancing, snowboarding, woodworking or yoga.

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Martin Larsen

Vice President

Martin Larsen lives in Kasson, MN. He is a fifth generation farmer, an environmental educator for Olmsted County and is studying hydro-geology at the University of Minnesota. Passionate about geology; Martin has facilitated numerous karst studies including groundwater dye tracing, spring monitoring and nitrate reduction studies. Other interests include GIS mapping, building scientific instruments and photography.

Michael Raymond

Safety Director/Dive Specialist

Michael Raymond lives in Eagan, MN. He is the diving officer for the National Cave Rescue Commission (NCRC), a lifetime member of the National Speleological Society (NSS) and its Cave Diving Section (CDS), and a member of other caving groups such as the Cave Research Foundation (CRF). Michael is a software engineer and an Army National Guard officer. Michael had attended numerous cave safety courses across the United States and occasionally conducts cave safety seminars in the Twin Cities. He enjoys traveling and has been to thirty five other countries.

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Janine Cross


Janine Cross lives in the Twin Cities metro area and has been an accountant for 30 years. A Certified Nonprofit Accounting Professional since 2008, Janine has provided services to many Twin Cities metro non-profit organizations. An avid lover of dogs, Janine also freelances as a pet-sitter on Janine has toured caves and mines in many locations in and out of the USA, especially in Fillmore County, Minnesota. Her love of the outdoors includes downhill and cross-country skiing, rock climbing, sailing, kayaking, mountaineering, bicycling, and camping.

Katharine Poylio


Katharine Poylio lives in the Twin Cities Metro area and has been a caver since her early teens.  She served as recording secretary for four other nonprofit organizations as well as Camp Counselor, Junior Leader, and 4-H Ambassador.  Katharine maintains the club’s liability release forms along with sign-up sheets. She is a Real Estate Accountant with the largest commercial real estate services and investment firm in the world.  She is a NOLS alumni with certification in wilderness first aid, and is certified by the American Heart Association in CPR/AED.  Katharine is a passionate nature enthusiast, animal lover, violinist and world traveler.

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Max Graybill

Dive Specialist

Max Graybill lives in Cannon Falls, Minnesota and is in the process of earning a degree in conservation. He has been diving since age 12, has accumulated over 250 dives (most of them wreck dives) and has been working as a dive professional for over two years. He also has ten specialty certificates and is no stranger to solo dives, including low and zero visibility diving. When not diving, caving, or studying, he works as a wilderness guide/climbing instructor and checks extreme sports off his bucket list.

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