Who We Are

Andrew W. Messenger, D.O.

DSC_5825 Dr. Messenger received his undergraduate and graduate degrees from Western Michigan University and his medical degree from Michigan State University’s College of Osteopathic Medicine. Dr. Messenger then went on to complete his internship at Flint Osteopathic Hospital in Flint, Michigan. Following his residency, Dr. Messenger made the decision to practice family medicine and soon after joined a group of physicians, who together established Clinton County Medical Center.

A Board Certified Family Practitioner, Dr. Messenger is a partner at Clinton County Medical Center, P.C. and is on active staff at Clinton Memorial Hospital in St. Johns, Michigan. Furthermore, Dr. Messenger is currently licensed to prescribe Suboxone, a prescription medicine and program to treat persons with addictions and dependencies to narcotics.

When he’s not in the office, Dr. Messenger can be found exercising, piloting small aircraft or spending time with his wife, Vicki and their four children.

Lars P. Andersen, Jr., D.O.

Dr. Andersen received his undergraduate degree at Huntington College in Indiana and graduated from Kirksville College of Osteopathic Medicine. He completed his internship at Carson City Hospital and is Board Certified in Family Practice medicine. Dr. Andersen has been caring for patients in the St. Johns area since 1975 and is on active staff at Clinton Memorial Hospital in St. Johns, Michigan.

Dr. Andersen has had the privilege of visiting Russia twice on mission trips with the First Baptist Church in St. Johns. He and his wife Kathy have three children and reside in St. Johns. Dr. Andersen enjoys going north to Suttons Bay with his family and participating in a variety of outdoor sports.


 Taylor Thelen, D.O.

Taylor Thelen, DO

Dr. Taylor Thelen was raised in Westphalia, MI and is excited to be back in Mid-Michigan to practice family medicine. Dr. Thelen attended Michigan State University for both his undergraduate and medical school studies. He received his doctorate from the MSU College of Osteopathic Medicine and completed his Family Practice residency at Munson Medical Center in Traverse City Michigan.  Dr. Thelen enjoys running,  biking, and golfing when he’s not spending time with his wife Chelsea and daughters, Mara and Ellis.

Dr. Thelen is currently licensed to prescribe Suboxone, a prescription medicine and program to treat persons with addictions and dependencies to narcotics.



Maria A. Thelen, RN, BSN, P.A.-C

Maria Thelen
Maria received her Bachelors in Nursing from Ferris State University and later continued her education at the University of Detroit where she received her Masters in Science as a Physician Assistant (PA). Prior to her Masters degree, Maria worked as an RN at the Sparrow Health System and St. Joseph Mercy – Oakland.

Maria has been a Physician Assistant at CCMC for more than seven years and is very happy to be working in her hometown of St. Johns. Maria enjoys spending time with her three children and relaxing in the Upper Peninsula at Whitefish Bay.



Bryanna Weber, PA-C – RD

Bryanna received her bachelor’s degree in dietetics at Central Michigan University and later continued her education at CMU receiving her Masters of Science as a Physician Assistant. Prior to her master’s degree, Bryanna completed a dietetic internship as well as worked as a dietitian at University of Michigan Hospital.

Bryanna resides in St. Johns and enjoys spending time with family and friends, traveling and outdoor activities.





Justin Morris, PA-C

Justin Morris

Justin received his bachelor’s degree in biomedical science at Central Michigan University and later continued his education at CMU receiving his Master of Science degree as a Physician Assistant. He was raised in Williamston, MI and has lived in St. Johns for the past 7 years. During his training, Justin had the opportunity to take part in a medical mission trip to Sierra Leone, Africa.  Justin spends much of his free time outdoors hunting, fishing, biking, and snowboarding. He is excited to be practicing family medicine in St. Johns, and proud to be part of a great local community.





Kristine Tuchek, PA-C

Kris Tuchek

Kristine received her Master in Science in Physician Assistant studies from Wayne State University in 2000. Upon graduation she worked in the Emergency Department of Ingham Regional Medical Center, now McLaren Greater Lansing, until 2014. Since then she has found her niche working in Urgent Cares.

She joined the CCMC family in December 2014 to help us get OUCH Urgent Care up and running. She is our primary provider at OUCH. Her extensive background in Emergency Medicine and Urgent Cares is a perfect fit for OUCH.





Karen Chase, DNP

Karen Chase

Karen received her Doctor of Nursing Practice through the University of Michigan in 2016. She is a certified family nurse practitioner.  She also earned her Bachelors degree in nursing through the University of Michigan. Prior to joining Clinton County Medical Center she worked as a registered nurse with experience in long term care, home care, and acute care. Karen’s hobbies include  biking, camping, gardening, and keeping  chickens.  She also enjoys visiting both of her sons serving in the United States Air Force.





Erin Griffith, NP-C


Erin’s specialty is adult and geriatric primary care. She has 8 years of nursing experience, and 18 years of experience with geriatric and developmentally disabled. She received her initial nursing degree from Baker College in Owosso and later earned her Master’s in Nursing as a Nurse Practitioner (NP) from South University in Novi. Prior to her Master’s degree, Erin worked as a Trauma/ER nurse at Sparrow Health Systems.

Erin is also raising her two children with her high school sweetheart in the Lansing Area, not far from where she grew up in Owosso.
© 2011 Clinton County Medical Center