Yosemite Medical Clinic Staff

Physician and Medical Director

Valerie Ohman, MD (Board Certified in Family Medicine)
Captain, US Public Health Service

Nurse Manager

Jennifer Marshall, RN
Commander, US Public Health Service

Staff Nurse

Tim Yett, RN-BC, MSN, PHN
Lieutenant Commander, US Public Health Service

Physician Assistant

Casey Nelson, PA-C
Lieutenant, US Public Health Service
U.S. Public Health 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

Last updated: November 22, 2017

Contact the Park

Mailing Address:

PO Box 577
Yosemite National Park, CA 95389


(209) 372-0200

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