Executive Leadership

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Dr. J. Tyler Whitaker, DO

Chief Executive Officer
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Sharmien Watkins

Chief Financial Officer
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Natalie Schaller, DO

Chief Medical Officer

Holly Bennett, ARPN, CNP

QA/QI Director
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Caroline Green

Interim Nurse Manager/ Case Manager

CHS Board of Directors

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Jordan Boss

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Latoya Shaw

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Debra Cooper

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Matthew Acker, MD

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Tracie Chandler

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Kent Farish, DO

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Robin Higgins

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Gabriella King

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Louise Ingram

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Dale Rolland

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Larry Hytche, MHA, PA-C

Larry Hychte is a skilled physician assistant who has proven his ability to lead teams, coordinate schedules, and represent healthcare professionals on various committees, fostering a collaborative and productive work environment. He has strong interpersonal and communication skills and is effective at facilitating information exchange in healthcare settings. He is dependable and committed to consistently delivering high-quality patient care. He holds his
Master’s in Healthcare Administration from OSU, and his Master’s in Physician Assistant Studies. In his spare time, Larry enjoys playing and watching sports, traveling, and is currently working on building a new community center for the town of Tallahassee.

Holly Bennett, ARPN, CNP

Holly Bennett is a distinguished Family Nurse Practitioner (FNP) and Director of Quality with 19 years of nursing experience. She graduated with a BSN from Samford University and an MSN as an FNP from Old Dominion University. Credentialed by AANP and licensed in Oklahoma, Holly holds Basic Life Support and Advanced Cardiac Life Support certifications. As the Director of Quality, Holly oversees patient safety initiatives and manages software adherence to regulatory standards. Her unique combination of clinical expertise, administrative skills, and commitment to quality and compliance positions her as a valuable healthcare leader. With extensive experience as a Primary Care Practitioner for diverse populations, Holly volunteered as a nurse on medical mission trips, free clinics, and mobile missions to underserved regions. Currently pursuing a Graduate Certificate in Population Health, she remains committed to enhancing her understanding of social and environmental determinants of health.

image of Dr. Glenna Wong-Johnson, MD

Dr. Glenna Wong -Johnson, MD

Dr. Glenna Johnson is a board-certified family medicine physician who has served as a staff physician at Crossover Health Services since 2022. Originally from Maryland, Dr. Johnson graduated in 2019 from Penn State College of Medicine in Hershey, Pennsylvania. She completed a family medicine residency with the “In His Image” Family Medicine Residency Program” in Tulsa, Oklahoma, in 2022. Her interests in medicine include preventative health and community health. She has enjoyed being a part of the North Tulsa community, where she lives with her husband and their daughter. In her free time, she enjoys reading, going on nature walks, and spending time with friends & family.

image of Natalie Schaffer, DO

Dr. Natalie Schaller, DO

Dr. Natalie Schaller has served as Chief Medical Officer of Crossover Health Services since August 2023. She earned her undergraduate degree from Minnesota State University, Mankato, double-majoring in Spanish and Human Biology. Following undergrad, Dr. Schaller attended Kansas City University for medical school and was awarded the National Health Service Corps Scholarship. After completing her Family Medicine residency in Tulsa, Oklahoma, she started as Medical Director of the FQHC in Iowa in 2013. Along with her educational background, Dr. Schaller brings ten years of experience as a Medical Director for a Federally Qualified Health Center (FQHC) in Storm Lake, Iowa, and a passion for serving diverse, under-resourced communities. In this role, she oversaw daily clinic operations, supervised and trained staff, implemented policies and procedures, and participated in inpatient coverage. She exercised creative problem-solving during COVID-19, creating an outpatient clinic for diagnosing and treating cases. Dr. Schaller was awarded ‘Provider of the Year’ among Iowa’s FQHCs in 2022. Proficient in Spanish, she has participated in multiple medical relief trips overseas to Ukraine, Afghanistan, Malawi, Kenya, and Nepal. She also volunteered for ten years with a non-profit empowering marginalized youth in Storm Lake, showcasing her dedication to health and wellness in children. Dr. Schaller blends her FQHC and volunteer experience to bring healing and restoration to the local community of Tulsa.

image of Dr. J. Tyler Whitaker, DO

Dr. Tyler Whitaker, DO

Dr. J. Tyler Whitaker is a board-certified family medicine physician currently serving as the Chief Executive Officer of Crossover Health Services in Tulsa, Oklahoma – a position he has held since 2023. Dr. Whitaker earned his Doctor of Osteopathic Medicine degree from the Oklahoma State University College of Osteopathic Medicine in 2012. In 2015, he completed his internship and residency, serving as Chief Resident, at In His Image Family Medicine Residency at St. John Medical Center in Tulsa.  Dr. Whitaker has remained a part of the St. John staff, serving  as a hospitalist caring for inpatients, both there, and at Tulsa’s Hillcrest Medical Center. Passionate about individual and community health and dedicated to domestic and global health outreach, Dr. Whitaker has volunteered on medical missions to Haiti, Iraq, Nepal, Nicaragua, and Ukraine. He and his family of five have lived and served in the community of North Tulsa since 2012. In his free time, Dr. Whitaker enjoys doing anything with sports and outdoor activities.

CHS Leadership

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