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Chapter Officers

Chapter President - Sharon Mulvehill, MD


Dr. Mulvehill was born in Houston, Texas and attended medical school at UT Southwestern in Dallas.  She was initially drawn to general surgery, then emergency medicine, before settling into a career in academic family medicine.  As the opioid crisis emerged she developed an interest in addiction medicine, eventually pursuing additional training and becoming board certified in addiction medicine. She has practiced at RiverStone Health in Billings, MT since 2005 and now shares her time with Rimrock Foundation as their Medical Director. Dr. Mulvehill has four grown sons, her best friends, and enjoys playing guitar in the soul/funk band Free Spirit SOUL.  

Chapter Treasurer - Tammera Nauts, LCSW, LAC


Tammera Nauts, LCSW, LAC is the Director of Integrated Behavioral Health with the Montana Primary Care Association. Tammera has broad experience in the substance use disorder and mental health fields, ranging from direct service to the administration of programs and services for all levels of care. She has served diverse populations that include youth and their families, probationers, parolees, women with special needs, employee groups, and clients with co-occurring disorders. She received a B.A. in Education from Western Washington University and her master’s degree in Social Work from the University of Washington. She holds a license in Clinical Social Work and Substance Use Disorders.

Chapter Secretary - Dan Nauts, MD, FASAM

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Dr. Nauts completed his undergraduate and medical education at the University of Michigan and joined an internal medicine group practice in Bellingham, Washington.  He left general internal medicine to develop his Addiction Medicine practice; since that time, he has been instrumental in the creation of inpatient programs for those suffering with substance use and co-occurring disorders, outpatient SUD programs, and medication assisted treatment services. Dr. Nauts is an independent contractor for the Montana Primary Care Association. He is a member of the Drug Utilization Board of Mountain Pacific Quality Health providing oversight to the Medicaid formulary, is recognized as a Fellow of the

 American Society of Addiction Medicine (FASAM) and is certified in the subspecialty of Addiction Medicine by the American Board of Preventive Medicine.  He is a faculty member of ASAM providing Data 2000 MAT waiver trainings and The Fundamentals of Addiction Medicine courses.

Immediate Past President - Robert Sherrick, MD, FASAM

board certified in Internal Medicine and Addiction Medicine through the American Board of Preventive Medicine.  

Dr. Robert Sherrick is Chief Medical Officer for Community Medical Services, a company that serves patients through over 50 Opioid Treatment Programs in 10 states.  He also works at an inpatient addiction treatment facility in Kalispell, Pathways Treatment Center, treating all forms of Substance Use Disorders and dual diagnosis patients. Dr. Sherrick has been providing Medication Assisted Treatment for Opioid Use Disorder since 2003, initially in an office setting using buprenorphine and subsequently with methadone in Opioid Treatment Programs.  He established a state-wide buprenorphine treatment program for VA Montana with extensive use of telemedicine.  He is 

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