Sonoma County Indian Health Project Dental Provider Team

Getting to know your Dental Providers
Phone: (707) 521-4600


Joel Berryhill DDS, Dental Director

Dr. Joel Berryhill attended the University of Oklahoma for his undergraduate studies and the University of Missouri for his dental degree. Dr Berryhill joined the Sonoma County Indian Health Project family in 1997. Prior to moving to California, he had a private practice in Tulsa Oklahoma for 25 years. He enjoys golf, his garden, traveling, and spending time with his grandchildren. It has been a rewarding experience for Dr. Berryhill to see SCIHP’s dental department and the organization grow to serve our community.


Peter Fong, DDS

Dr. Fong attended the University of British Columbia in Vancouver for undergraduate studies, obtaining a B.S. In zoology. Dr. Fong attended Marquette University School of Dentistry in Milwaukee, WI for dental education, obtaining a DDS degree. Dr. Fong then went on to complete a one-year General Practice Residency (GPR) Program at Valley Medical Hospital and at the VA Hospital, both located in Fresno, CA to further enhance dental knowledge and experience, as well as performing hospital dental cases. Other than dentistry, outside interests include watching movies and enjoying new and different food.


Ryan Hillstead, DMD

Dr. Hillstead is a native of Sonoma County Dr. Hillstead received a Bachelor of Science degree in biology from Brigham Young University. In 2013, Hillstead attended Roseman University of Health Sciences College of Dental Medicine where he earned his DMD degree. He returned home to Sonoma County in 2017 to begin his career in dentistry. When not practicing dentistry, Hillstead enjoys spending time with his newborn daughter, water skiing, snowboarding, golf, and traveling with his wife Brighton. Dr. Hillstead is the second generation in his family to work for SCIHP, his father was a long-time member of the SCIHP family.


Asterita Machado, DMD

Dr. Machado went to Centro Escolar University, Manila, Philippines for her undergraduate work and for her dental school education earning a degree Associate in arts and DMD, respectively. Dr. Machado has worked in a private practice for 17 years in her home country. Dr. Machado moved and lived in Ontario, Canada for 4 years before emigrating to the United States in 2002. Prior to joining Sonoma County Indian Health Dental Department in 2008, she worked in a private practice. She has been working full time at SCIHP since 2008. Dr. Machado loves to bake and enjoy food, wine and traveling with her husband.


Joseph Rutkowski, DDS

Dr. Joseph Rutkowski is a general dentist who obtained his degree from the University of Pittsburgh School of Dental Medicine in 2007. After graduation Dr. Rutkowski joined the dental team here at Sonoma County Indian Health Project. He has been caring for this community for eleven years. In his down time, Dr. Rutkowski enjoys traveling the world with his wife and daughter. His hobbies include cycling, painting and listening to his record collection.


Amy Wong, DDS

Dr. Wong earned her Bachelor of Science degree in Molecular Cell Biology from University of California in Berkeley. Dr. Wong then received her doctoral degree from University of Southern California School of Dentistry in 2003. Dr. Wong is a proud dental team member since 2006 and enjoys providing dental care to patients at Sonoma County Indian Health Project. Aside from her profession, Dr. Wong enjoys traveling and spending time with family.