Mark and Joan Unnerstall, Washington, announce the engagement of their daughter, Erica Unnerstall, Eureka, to Zach Ryals, Eureka, son of Bob and Kathy Ryals, House Springs.

Erica graduated from St. Francis Borgia Regional High School in 2002 and Fontbonne University in 2006.

Zach graduated from Valley Park High School in 2005 and from Missouri University of Science and Technology in 2009.

The couple plan a July 12, 2014, wedding at 1:30 p.m. at St. Francis Borgia Church, Washington.