Curtin Winsor III, the co-founder and executive chairman of the Bank of Georgetown who served on the boards of the National Zoo, Washington National Opera and other organizations, died Dec. 11 at Virginia Hospital Center in Arlington County after a heart attack. He was 49. His wife, Deborah Winsor, confirmed his death.

Mr. Winsor, who was a Georgetown resident, launched the Bank of Georgetown with Mike Fitzgerald in 2005. Since then, it has expanded to nine branches and has assets of $767 million.

Earlier, Mr. Winsor had been a founding partner of Columbia Partners Investment Management, a money-management firm based in Chevy Chase. He had also worked at the old Riggs Bank as an investment banker and as an executive of a family-run chemical manufacturing business in West Virginia.

Mr. Winsor was born in Washington and was a 1981 graduate of the private Landon School in Bethesda. He was a 1985 graduate of Colorado College and received a master’s degree in international relations in 1987 from the University of Cambridge in England.

As a member of the board of the National Zoo, Mr. Winsor took a strong interest in the zoo’s breeding program for endangered cheetahs. He was on the boards of the Starlight Children’s Foundation and Fight for Children, groups that provide educational materials and grants for children.

Mr. Winsor was a vestry member and Sunday school teacher at the Episcopal Christ Church Georgetown and was on the executive committee of the now-defunct Washington Scholarship Fund.

He was a trustee of the National Taxpayers Union, an organization seeking to reduce taxation levels and the size of government. He also served on the national advisory board of Trout Unlimited, a group dedicated to restoring the natural habitats of trout and salmon.

Mr. Winsor and his family had a summer home in Nova Scotia, where he enjoyed boating. He was also a longtime lover of opera.

His marriage to the former Noelle Shepard ended in divorce.

Survivors include his wife of 11 years, Deborah Redhage Winsor of Washington; a daughter from his first marriage, Devon Winsor of Washington; two daughters from his second marriage, Elizabeth Winsor and Julia Winsor, both of Washington; his parents, Curtin Winsor Jr., a former U.S. ambassador to Costa Rica, and Ann Winsor, both of McLean; and four sisters, Anita Winsor Edwards of Alexandria, Monica Winsor Mailman and Cristina Winsor, both of New York City, and Rebecca Winsor of San Francisco.