Medical Staff

Dr. William Vandivier DO
Dr. Vandivier has over 19 years of health care experience as a practicing physician, a physician expert in medical informatics consisting of electronic health record system implementation, management, and design, as well as serving in executive level leadership roles. His most recent role was serving as the president and chief physician executive for MercyOne Central Iowa Medical Group, in Des Moines, Iowa, where he was responsible for employment of all the providers as well as all the staff and clinics in the ambulatory space.
Dr. Vandivier is board certified in family practice as well as medical informatics. He is a member of the American Academy of Family Practice, the American Medical Association, and the American Medical Informatics Association.
In his spare time, Dr. Vandivier enjoys motorcycles and music.
Dr. Vandivier is looking forward to being a part of Appleton Area Health and serving the community for all their health care needs.
Specialty:
Family Medicine
Education/Residency:
Grandview College
Des Moines University
Dr. Utpal Chakravorty
Welcome back Dr. Utpal Chakravorty! Dr. Chakravorty was previously with AAH and we are delighted that he has returned as he brings 50 years of knowledge and experience to the AAH team.
Dr. Chakravorty graduated from the Gauhati University in India in 1972. Following his graduation, his family moved to England where he practiced internal medicine and geriatric medicine for over 12 years. Following this he practiced in Saudi Arabia and England before moving to the United States. Dr. Chakravorty has experience in family medicine, internal medicine, gerontology, urgent care and more.
Dr. Chakravorty will be seeing patients for:
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Preventative care and wellness exams for men and women
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Well-child exams and immunizations
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Acute/Urgent illnesses
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Chronic care management of illnesses such as diabetes, high blood pressure, asthma, heart disease, and more!


Dr. William Lee, FACS
Dr. William Lee received his Bachelor’s degree at the University of South Dakota and attended medical school at the University of Iowa College of Medicine in Iowa City, Iowa. He also completed his surgical residency at the Kalamazoo Center for Medical Studies/Michigan State University in Kalamazoo, Michigan. He is certified by the American Board of Surgery.
Dr. Lee has worked as a general for over 25 years and has specialized in bariatric surgery for more than 15 years. He has practiced in Minnesota and South Dakota his entire career.
As a member of the American Board of Surgery, Dr. Lee performs a variety of surgical procedures and has had extensive experience in gastrointestinal and bariatrics and can perform a broad array of general surgical procedures.
Dr. Charles Keller
Dr. Keller is a highly accomplished physician-leader who has a distinguished career specializing in family medicine, urgent care, and hospice care.
Dr. Keller comes to Appleton Area Health following several years in Iowa’s MercyOne medical system where he held several leadership roles. Dr. Keller is a graduate of the University of Iowa, and George Washington University School of Medicine. Dr. Keller is certified by the American Board of Family Medicine and is a fellow of the American Academy of Family Practice.
“I am delighted to have the opportunity to join the remarkable team at Appleton Area Health. My family and I are also excited to become a part of a wonderful community such as Appleton. Providing outstanding care to patients in their own backyard is vitally important to the overall health of rural Minnesota.” - Dr. Charles Keller
Away from his time at the hospital, Dr. Keller enjoys family time with his wife Stephanie and their three daughters.


Elizabeth Charles APRN-CNP, FNP, CNM
Philosophy of Care:
“I'm here to serve the people of the community by providing holistic care combined with continued education so they are able to live their best life. What I enjoy most about working in a rural clinic is getting to know my patients, their stories, and the opportunity to care for the whole family.”
Specialty:
Family Practice
Women’s Health
Midwifery
Education:
Indiana University of Pennsylvania
University of Cincinnati
Board Certifications & Memberships:
American Association of Nurse Practitioners
American College of Nurse-Midwifery
American Midwifery Certification
Tonya Diggins APRN-CNP, FNP, CNM
Philosophy of care:
"Every birth is an opportunity to make a connection. Pregnancy can be a raw and vulnerable time and I believe in finding the best possible fit so that you feel confident and comfortable in your healthcare decisions. My practice allows me the opportunity to build relationships based on communication, respect, and trust from birth throughout the entire lifespan!"
Specialty
Family Practice
Women’s Health
Midwifery
Education:
University of Minnesota
Board Certifications & Memberships:
American Nurses Credentialing Center
American Midwifery Certification


Crystal Turner APRN-CNP, FNP
Philosophy of Care:
I believe in customizing care to respect my patient's individual
beliefs, recognizing the importance of both physical and mental well-being. I believe in educating patients on maintaining their health and disease prevention to promote quality living.
My goal is that patients become a partner in their own care and be able to gain control and understanding of their own health and well-being.
Specialty:
Family Practice
Education
Chamberlain University
Frontier Nursing University
Board Certification
American Academy of Nurse Practitioners
Deb Colón APRN-CNP, FNP, PMHNP
Philosophy of Care:
"I believe in treating the whole person by taking into account mental, physical, and social factors. I am committed to working together to provide the best possible care for our patients. Each patient is different, and I am passionate about treatment plans based on each person's needs, values, and beliefs because my primary role is to help you live your best life!"
Specialty:
Behavioral Health Medication Management and Therapy
Education:
North Dakota State University
University of Cincinnati
Board Certifications & Memberships:
American Nurses Credentialing Center
American Psychiatric Nurses Association
American Association of Nurse Practitioners


Lesa Thielke APRN-CNP, FNP
Lesa received her Associate degree in nursing from MN West in 2017, her Bachelor of Science in Nursing degree in 2019, and completed her Master of Science in Nursing from Clarkson College in August 2022.
Lesa has worked at Appleton Area Health since 2019, and looks forward to continuing to serve the community she grew up in. She has a variety of nursing knowledge ranging from surgery, dialysis, long-term care, wound care and ER. She chose to further her nursing education as a family nurse practitioner to help others achieve and maintain their health by building a trusting relationship from the beginning to end of life. She has a passion for diabetes education and looks forward to offering these services to the community.
Lesa grew up in Appleton. She resides in Holloway with her husband Rod and 3 sons Daniel, Landan, and Tyson. In her free time, she enjoys camping, boating, fishing, and spending time with family and friends.
Lesa will begin seeing patients in early 2023.
Kelsey Tollefson MSW, LICSW
Philosophy of Care:
"I believe that mental and emotional health is just as important as physical health. I'm dedicated to normalizing mental health treatment and reducing the stigma associated with mental health disorders! I strive to provide treatment in a safe and comfortable setting to create a personalized treatment plan that addresses your concerns. I understand the importance of integrated care where all providers work as a team to deliver exceptional care for every patient!"
Specialty:
Cognitive Behavioral Therapy
Behavioral Health Therapy
Dialectical Behavior Therapy
Accelerated Resolution Therapy
Education:
South Dakota State University
Minnesota State University
Board Certifications & Memberships:
National Association of Social Workers


Lisa deCathelineau MA, LMFT
Philosophy of Care:
"My career has been dedicated to assisting individuals and families through their personal and family unit struggles. My passion is to create a safe environment for self-discovery and healing; walking alongside my clients to find the space they need to move forward through their unique challenges. I find great value in using a holistic approach to treating mental, emotional and physical health by accessing and integrating services wherever possible."
Specialty:
Cognitive Behavioral Therapy
Behavioral Health Therapy
Dialectical Behavior Therapy
Education:
University of Minnesota, Morris
Alfred Adler Graduate School
Board Certifications & Memberships:
Minnesota Board of Marriage and Family Therapy
American Association for Marriage and Family Therapy
Minnesota Association for Play Therapy