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Board of Directors

Maryann McMahon, OP, President

Sister Maryann McMahon is president of the Racine Dominicans. A nurse practitioner with MSN and FNP degrees from the University of Wisconsin-Oshkosh, she has served in multiple capacities.


Before her election as president of her community, she was the Executive Director of HOPES Center, serving mental health and social service needs of Racine’s poor and homeless.

Agnes Johnson, OP, Vice President

Sister Agnes Johnson holds a B.S. in medical technology from Dominican College, Racine, and an RN from Deaconess Hospital in Milwaukee. She has served as vice-president of the Racine Dominicans. Before being elected to leadership in her community, she was an RN case manager for Home Health United in Portage, a nonprofit health care agency.

Shari Geertsen, Secretary/Treasurer

Shari Geertsen has been the Director of Finance for the Racine Dominicans since 2002. She holds a B.S. degree in Business Administration and Accounting from the University of Wisconsin-Parkside. She also serves on several non-profit boards and is a trustee for several congregations.


Her prior work includes Controller and Accounting Manager in for-profit corporations for more than 10 years.

Bernie Flores, NP

"My goal as a nurse practitioner is to partner with my patients to achieve their highest level of wellness possible. Together through teaching, guidance, and current evidence-based medical information, we can achieve an improved level of health for each patient."


Bernie Flores has a Bachelor of Science in Nursing degree from Marian College in Fond du Lac, Wisconsin, and a Master of Science in Nursing (Geriatric Nurse Practitioner) from Concordia University in Mequon, Wisconsin.

Gary Mohn

Gary has an MS in Health Administration from North Texas State University and is a Licensed Nursing Home Administrator. 

Gary has held numerous leadership roles in older adult health care ministries, including CEO of Alexian Village in Milwaukee, CEO - East Region for Ascension Living and most recently an interim role of Vice President, CCRC Operations Liaison at Lutheran Life Companies. Gary has enjoyed developing leadership teams, developing and implementing strategic plans, overseeing new and rehab construction projects and promoting an array of operational quality services for older adults in all aspects of life.

Gary and his wife have 5 boys and 9 grandchildren.


Gregory Anderegg

Greg Anderegg retired from SC Johnson in 2015 after a 36-year career with the company, where he focused on advancing company values and community interests in the communities around the world where SCJ does business, with a primary focus on the headquartered community of Racine. After his retirement, from 2016 to 2020, he served as an advisor to the Johnson Foundation at Wingspread for their Resilient Communities Initiative.

Throughout his career, he was engaged in an array of local community organizations and initiatives, including Board President for: All Saints Foundation, Racine Area United Way, Rotary Club of Racine and the 21st Century Preparatory School. He was a part of several national initiatives, including the President's Council on Sustainable Development and the Advisory Board for the Center of Corporate Citizenship at Boston College.

Since retiring, Greg has remained active as a community volunteer. He co-chaired a major fundraising efforts to build a new memory care wing at St. Monica's Senior Living. He currently serves on the board at the Racine Art Museum, Siena on the Lake, the Racine Community Foundation and the Wisconsin Humane Society.

He lives in Racine with his wife Carol. Beyond his volunteer work, Greg pursues these passions: travel, golf (with apologies to all), reading, music and spending time with this family.




Susan Boland, Executive Director (ex officio)

Susan Boland has been the Executive Director for Siena on the Lake since October 2018. She holds a BS in Nursing from St. Xavier University and an MS in Nursing from Rush University.


Susan serves on several non- profit boards within the community. Prior to joining Siena on the Lake, Susan served in multiple leadership roles for 23 years within Wheaton Franciscan Healthcare – All Saints and retired as the President of Ascension – All Saints in 2017.

Alex Ostrov (ex officio)

Alex Ostrov has worked in multiple capacities since joining the organization in 2016, currently serving as Accounting Manager.  He holds a Bachelor of Business Administration in Accounting from the University of Wisconsin-Milwaukee and is pursuing his Masters of Business Administration at Concordia University. 


Through his service to various non-profits in southeastern Wisconsin, he brings over a decade’s worth of financial experience to Siena on the Lake. 

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