Sarah Collier, Topeka, and Justin Mitchell, Topeka, have announced their engagement.She is the daughter of Paul and Jackie Collier, Topeka.He is the son of Marcia Mitchell, Ottawa.She graduated from Seaman High School, Topeka, in 2003 and Washburn University in 2009. She works at Kansas Children’s Service League as a family support specialist.He graduated from Ottawa High School in 2000.  He works in the Seaman School District as a bus driver.The wedding is scheduled for Nov. 7, 2009, at Topeka.