Meet our MedTreks Faculty Team!
At MedTreks, our trips are led by a dedicated team of instructors with years of experience in medicine, education, and adventure travel. The MedTreks faculty includes physicians, nurses, paramedics, and global health leaders who bring a wide range of skills and stories to the table.
Whether they’re teaching in the Galápagos Islands or guiding a course in the backcountry, our faculty are passionate about sharing practical knowledge in real-world settings. They love creating an environment where learning is meaningful and fun.
Ari Rasori, RN, FNP
Ari Rasori is a passionate nurse practitioner with a deep love for adventure, wilderness, and travel medicine. As the founder and owner of MedTreks International, Ari brings incredible depth of real-world insight and cross-cultural understanding to every MedTreks experience. She has over three decades of experience traveling and guiding across six continents,
With over three decades of experience traveling and guiding across six continents, Ari has taught travel medicine and global health in diverse settings. She also founded MedTreks Kenya. MedTreks Kenya is a global health initiative that partners with Village HopeCore International. They offer skills-based training and mentorship to local healthcare teams. In addition, Ari is a certified instructor in Wilderness Life Support for the Medical Professional (WLS:MP). As well as Wilderness First Aid (WFA), and Wilderness First Responder (WFR).
Undoubtedly, her teaching style is rooted in a genuine enthusiasm for helping fellow medical professionals expand their out of hospital skills. When Ari isn’t designing trips, planning courses, building itineraries, or picking up shifts in the ER she’s probably hiking with her dog! Ariane also loves practicing yoga, sharing good food with friends and dreaming up future adventures.
Ari’s life and work reflect her belief that medicine, adventure, and human connection are powerful forces for both personal and professional transformation. She’s thrilled to share that journey with the growing MedTreks community.
Phil Rasori, MD
Dr. Rasori teaches and consults in the fields of international health and travel medicine. For the last twenty years, he has led accredited, wilderness medicine and travel medicine field seminars for physicians to all the continents. This includes programs to countries like: Kenya, Tanzania, New Guinea, Peru, Costa Rica, Ecuador, India, Nepal, Bhutan, Brazil, Mexico, Guatemala, Thailand, Vietnam, and Antarctica.
He is a long time member of the Wilderness Medical Society and has lectured frequently at their national conferences since 1990. For 18 years, Dr. Rasori taught travel medicine and international health. This has been as part of the Department of Family and Community Medicine at the University of California, San Francisco School of Medicine.
Likewise, he is the co-founder and and Medical Director of a health program in Kenya, Village HopeCore International since the year 2000.
Sheryl Olson, RN
Sheryl Olson grew up in Wyoming and Colorado. Instructed by her father, she gained a passion for being in the outdoors and fell in love with adventure. She was a backpacking guide in the Colorado mountains for 10 summers. After graduating from college, she practiced her nursing profession for over 40 years, including 10 years as an ICU/CCU nurse and 18 years as helicopter flight nurse. Overlapping with her clinical career was her passion for educating others.
For the past 25 years she has been a teacher/instructor of Wilderness Medicine and Wilderness Safety and Survival. She’s taught at conferences and on adventure trips world-wide. Also, she believes that education and adventure go hand in hand and has guided and instructed on treks to Everest Base Camp, Mt. Kilimanjaro, Mt. Blanc, Patagonia and other beautiful places in the world.
Rivers in Costa Rica, Chile, California, Oregon, and Montana are some of her favorite places to raft, kayak, and educate others who want to learn more about Wilderness Medicine! Sheryl makes her home in Manitou Springs, CO. And along with her husband Larry Moore, and together they continue to enjoy the outdoors of doors hiking, mountain biking, paddle-boarding, rafting, backpacking, and backcountry skiing.
Dr. Christopher Van Tilburg
Christopher Van Tilburg is an American physician, rescue mountaineer, and award-winning author of 11 books, including two previous mountain rescue memoirs. Dr. Van Tilburg works in the emergency room, in clinic, and at a ski resort at the base of Oregon’s legendary, lethal Mount Hood.
Furthermore, he is medical director for four search and rescue teams. He is also chair of Mountain Rescue Association’s Medical Committee, and a USA delegate to the International Commission for Alpine Rescue. He serves as the local Public Health Officer and Medical Examiner. He has worked as an expedition physician on six continents, and as a cruise ship doctor. Also as team leader on five humanitarian medical trips to Haiti.
From the Wilderness Medical Society, he received the Dian Simpkins Award for Service in 2011, the Haiti Humanitarian Research Award in 2013, and the Ice Axe Award for Service in 2014. He is emeritus editor of Travel Medicine News and emeritus editor of Wilderness Medicine Magazine.
Brad L. Bennett, PhD, Paramedic, FAWM, FACSM, Captain, Medical Service Corps, U.S. Navy (Ret)
Dr. Bennett is an applied physiologist who spent 27 years in the U.S. Navy conducting biomedical research, development, and medical education. He also trained military operational personnel serving in austere environments. He has researched and taught the prevention and treatment of environmental hazards such as heat, cold, altitude and undersea medicine.
This member of our team trained as a Navy Department Deep Sea Diving Officer and is a Master Diver, PADI. He is an adjunct Professor and former Vice Chairman, Military and Emergency Medicine Department, F. Edward Hébert School of Medicine. This is at the Uniformed Services University of the Health Sciences, Bethesda, Maryland. He served as President, Wilderness Medical Society, and has served on the Committee on Tactical Combat Casualty Care, Dept of Defense since 2003.
To sum it all up, currently Dr. Bennett serves as a Section Editor, Wilderness and Environmental Medicine journal, and writes a quarterly article on tactical (trauma) medicine and other articles for the Wilderness Medicine Magazine. He is an avid traveler, and a nature and underwater photographer. He currently resides on the York River in Virginia, and is often found boating and kayaking.
Dr. Christian Dean
Dr. Christian Dean is a family medicine trained hospitalist based in Missoula who is passionate about wilderness, travel, and sports medicine. The mountains in Maine and Colorado inspired him to earn a B.A. in Molecular, Cellular, and Developmental Biology at the University of Colorado-Boulder.
This was before completing an M.S. in Biomedical Sciences at the University of North Texas Health Science Center. He later earned his D.O. degree from the Texas College of Osteopathic Medicine in Fort Worth. Dr. Dean chose to attend an osteopathic medical school to better understand musculoskeletal ailments. He also did so to develop a more holistic approach to medicine.
He completed Family medicine residency at Methodist Charlton Medical Center in Dallas. Then he earned board certification from the American Board of Family Medicine and the American Osteopathic Board of Family Physicians. After completing residency, he returned to the mountains. In Jackson Hole he practiced inpatient and outpatient medicine. In addition to being the team physician for the Moose Hockey team and doing ski patrol at Snow King.
Meanwhile, he continued to expand his medical expertise and become more involved with teaching. He worked for two years doing primary care with Swedish Hospital in Seattle. Then he spent almost three months as a hospitalist at the onset of COVID pandemic in New York City. He now calls the mountains surrounding Missoula home. Now he works as an adult hospitalist when not being a physician on the sideline, ski hill, or remote expedition.
Dr. Dean has earned his Diploma in Mountain Medicine through the medical commissions of UIAA and ICAR. He is a Fellow of the Academy of Wilderness Medicine earned through the international Wilderness Medical Society. Similarly, he also runs a business, MyDocInTow, LLC. This is where he offers compassionate and comprehensive on-site or on-call medical direction and advisory on expeditions and at-sea.
Lainey Yu, MD
Next up in our MedTreks Faculty is Elaine (Lainey) Yu. Lainey is a Bay Area native who grew up in the mountains and on the water. She found her passion for wilderness medicine during medical school and is currently living her dream as a wilderness medicine fellow at UCSD. When not working in the ED or teaching everyone around her about wilderness medicine, she can be found in the mountains, or underwater. She is an AWLS instructor for MedTreks.
Carol Wilder, MD
Dr. Wilder earned her medical degree from The Medical College of Wisconsin and went on to complete her residency at St. Anthony Family Practice Residency in Denver. In 2007 she completed a fellowship in sports medicine at Utah Valley Regional Medical Center. After practicing for many years in Seattle at The Sports Medicine Clinic, Dr. Wilder moved to the Rogue Valley. There she joined Valley Immediate Care to help in the expansion of their Orthopedic and Sports Medicine department.
In addition, she is excited to be starting her own personal business venture. It’s a virtual wellness coaching program aimed at helping perimenopausal athletes. It has a focus on strength training, proper nutrition and injury prevention. Dr. Wilder is no stranger to athletics and outdoor adventure. As a collegiate swimmer and team captain at the University of Wisconsin she participated at the NCAA Division I level.
Then, while living in Hawaii she enjoyed a state championship win as an outrigger paddler and participated in the grueling Molokai Challenge. That was a five hour outrigger race across the Molokai channel. This is a prestigious outrigger paddling event in which participants from all over the south pacific race. As a young mother, Carol and her family of 3 sailed from Seattle to Hawaii, a 21 day adventure! A native to the Pacific Northwest, Dr. Wilder now enjoys snowboarding, mountain biking, and rafting on the local rivers with family and friends.
Dr. Mila Rojas, Medical Spanish Online Course Faculty
Another member of our MedTreks Faculty is Milagros Rojas who is a medical doctor from Venezuela. She has been part of the Endocrine-Metabolic Research Center “Dr. Félix Gómez” for over nine years! Mila’s curiosity as a medical researcher has led her to become interested in numerous topics. Her work has been published in different peer-reviewed journals, and she is especially interested in mental health and psychiatry.
However, Mila is all about empowering others with knowledge! This has led her to work as a creator of continued education resources as well as content designed for the general public. Her curiosity doesn’t end with medicine! Traveling, getting to know the people and medical practices in countries such as Colombia, Argentina, and Costa Rica is something she also loves. Still, she enjoys immersing herself in new cultures, exploring the beautiful landscapes and trying delicious food everywhere she goes.
Angie Hanchett, RN. MedTreks Kenya Faculty, Yoga Instructor & Retreat Leader
Her passion for yoga began in the Bikram Yoga classroom 15 years ago. She has completed extensive workshops and participated in Bishnu Charan Gosh yoga cups. Her teaching certification is from Soma Yoga Institute and derives alignment concepts from the Anusara tradition.
Angie strives to offer a well rounded practice that satisfies athletic cravings, mystical curiosities, and safe postural alignment in the body. Her personal yoga practice is the sacred cornerstone to her career as an emergency room nurse.
She lives for ocean activities and started her passion for public safety with the San Diego Lifeguards. Teaching CPR/First Aid and learning about the cultural perspectives of healthcare in global settings is another of her passions. Her personal mission is to inspire wellness by empowering people with healthcare education. She is currently on a sabbatical sailing a 30 foot sailboat with her boyfriend in Baja California.
Chelsea Tersavich, PA-C
Chelsea Tersavich, is a psychiatric clinician with extensive experience in mental health care. She has conducted psychiatric evaluations and facilitated ketamine therapy sessions for over 1,000 Mindbloom clients. Passionate about community service, she volunteers with underserved populations, focusing on sustainable lifestyle changes with limited resources.
Also, she earned her master’s degree through the Interservice PA Program. She gained extensive mental health and primary care experience during her Army career. That was where she treated thousands of Soldiers as a Battalion PA, travel medicine expert, and aviation clinic Medical Director.
Additionally, she is currently pursuing a Doctor of Medical Science degree in Global Health, aiming to support organizations internationally once complete.
Nicole Gregoire, PA-C
Moreover, during PA school, she was introduced to wilderness medicine. This exposed a whole new world that combined her love of medicine and the outdoors. Plus, her feeling of responsibility to care for those around her in every setting. She is an educator at heart and is excited to share her knowledge and experience with you.
Thanks for reading about our MedTreks Faculty!
Lastly, whether you’re learning by the ocean, in the mountains, or alongside a local community, our faculty are here to support, and guide you every step of the way. We’re incredibly proud of this team… and we can’t wait for you to meet them on your next MedTreks adventure.
Curious about the team behind the scenes? Click here to meet our incredible all-female office staff.
