Rick and Tracy Zwingelberg of 5617 Ridgeline Drive have announced the engagement of their daughter, Emily Rebecca Zwingelberg, to Christopher Donald Elster. He is a son of Dr. Steven and Divina Elster of Town and Country, Mo.

The bride-elect, of Alton, is a 2002 graduate of Quincy High School and is a dental student at Southern Illinois University School of Dental Medicine. She plans to graduate in 2009. Miss Zwingelberg is a member of Xi Psi Phi dental fraternity.

The prospective bridegroom, of St. Louis, is a 2004 graduate of the University of Missouri-Columbia and a 2007 graduate of St. Louis University School of Law. Mr. Elster is an attorney.

A July 12 wedding is planned in Cathedral Basilica in St. Louis.