Yosemite Medical Clinic Staff

 

Crystal Irwin-Warren, DO, PharmD, Clinic and EMS Medical Director

Board-certified in Emergency Medicine

Dr. Warren serves as the Yosemite EMS Medical Director, works as a physician in the Yosemite Medical Clinic, and is a lieutenant commander in the US Public Health Service. She completed her residency program at the Los Angeles County + University of Southern California Medical Center and is board certified in Emergency Medicine by the American Board of Emergency Medicine. She continues to practice Emergency Medicine as a locum and per-diem physician in a variety of practice settings from small, rural critical access hospitals to large, academic centers. Her passion for medicine is rooted in providing exceptional and accessible care for the community and visitors of Yosemite National Park. She is an enthusiastic teacher of medical students, residents and EMS providers. Her areas of clinical practice at YMC include women’s health, substance abuse treatment, mental health and urgent care conditions. Outside of medicine, Dr. Warren enjoys climbing, trail running, yoga, travel, and spending time with her husband and their dog, Tioga.

 

Alyson “Aly” Rose-Wood, DrPH, MSc, Health System Administrator

Aly Rose-Wood is a commander in the US Public Health Service. CDR Rose-Wood started as the health system administrator for Yosemite National Park in September 2024. She comes to Yosemite from the Centers for Disease Control and Prevention in Atlanta, Georgia. Aly’s 17-year federal government career has focused on hepatitis and HIV elimination, migrant health, vector-borne diseases, workforce development, and the delivery of rural health care. For five years she had responsibility for the Western Hemisphere portfolio in the Office of the Secretary of the U.S. Department of Health and Human Services. She received the HHS Secretary’s 2014 Award for Excellence in Management for her efforts on behalf of the U.S.-México Border Health Commission, a presidential commission co-chaired by the secretaries of health of the United States and Mexico. Her research background has focused on hantavirus, malaria, and cross-border HIV care transition. A graduate of Trinity University (Political Science and Literature, 2003), Harvard (Epidemiology, 2009), and the University of North Carolina at Chapel Hill (Health Leadership, 2020), she was a water and sanitation Peace Corps volunteer in Morocco and spent her childhood in Botswana, Ethiopia, Honduras, and Mali. In her younger days, Aly worked as a whitewater raft guide, leading expeditions down the Omo and Blue Nile Rivers in Ethiopia and multi-day river trips out of Moab, Utah.

 

Brittany Dover, Registered Nurse

Brittany Dover is a registered nurse with a varied background in both clinical and community healthcare. A Phoenix native, Brittany began their career in the US Army Reserve as an LPN, where they provided BLS training and emergency trauma education to local communities. During this time, they also worked as a contract nurse for the Indian Health Service in a specialty clinic, delivering vital care to underserved populations. Continuing their education, they earned a BSN from Grand Canyon University. Brittany gained experience on a medical/surgical floor before transitioning to the ICU at Barrow's Neurological Center. During their time at Barrow’s, they also served as a medic in the Arizona National Guard, ensuring unit readiness and supporting other units with medical care. Brittany later played a key role in administering vaccinations at state-run mass vaccination clinics in response to the COVID-19 pandemic and provided nursing support for outpatient services. Recently, they relocated to Yosemite National Park with their spouse, who works in EMS, to pursue opportunities at the Yosemite Medical Clinic. In this role, they are expanding their skill set while serving the community in a unique and challenging environment, continuing their passion for patient care and service.

 

Adriana S., Registered Nurse

Originally from Germany and then the East Coast, Adriana Sabella has been living in Reno, Nevada and enjoying the beautiful Sierra Nevada for the last seven years. Her background in nursing is in the ER and the ICU. She values the variety of experiences and the meaningful connections she forms with patients and coworkers. Adriana first visited Yosemite in 2018 and was deeply inspired by the place, the beauty, the climbing, and the people. She’s now excited and grateful to participate in this community.

 

Kyra Stiehl, Medical Support Assistant

Kyra Stiehl holds a B.S. in public health, sociology, and outdoor leadership from Miami University. She has a myriad of work experience from emergency preparedness, public health research, and pharmacy work to an Indiana health department as a clinical support specialist. Kyra is also wilderness first aid certified and a Leave No Trace trainer, amongst other certifications. Originally from Ohio, she moved out to California post-college and got married in Yosemite. It has always been her dream, personally and professionally, to work for NPS—let alone Yosemite—as it is a perfect intersection of her interests in health and environmental work. In her free time, she enjoys backpacking, coffee shops, and spending time with her husband and her dog, Sierra.

 

Jacqui Returra, Medical Receptionist

Joining NPS and the Yosemite Medical Clinic in 2023, Jacqui Returra is the only medical receptionist in the entire National Park Service!

 

What is the U.S. Public Health Service Commissioned Corps?

The U.S. Public Health Service Commissioned Corps is an elite team of more than 6,500 full-time, well-trained, highly qualified public health professionals dedicated to delivering the Nation's public health promotion and disease prevention programs and advancing public health science. Driven by a passion for public service, these men and women serve on the frontlines in the Nation's fight against disease and poor health conditions.

As one of America's seven uniformed services, the Commissioned Corps fills essential public health leadership and service roles within the Nation's Federal Government agencies and programs.

The mission of the U.S. Public Health Service Commissioned Corps is to protect, promote, and advance the health and safety of our Nation. As America's uniformed service of public health professionals, the Commissioned Corps achieves its mission through:

• Rapid and effective response to public health needs
• Leadership and excellence in public health practices
• Advancement of public health science