Britney Book, Executive Director

Britney Book is the new Executive Director for Siouxland CARES. While she is new to the position, her knowledge and appreciation of the organization spans a number of years. Britney served on the Sioux City Mayor’s Youth Commission and its Executive Council in high school (to which she cannot praise enough!). Following her graduation from the University of Nebraska-Lincoln, she moved back to the Siouxland area and immediately became an Adult Advisor with the Youth Commission.  She joined the Siouxland CARES board in 2014 and assisted with its social media efforts. In August 2016, Britney joined the Siouxland CARES staff as the Assistant Director and Teen Court Coordinator. In October 2017, Britney became the Executive Director for Siouxland CARES.

Britney came to Siouxland CARES with over five years’ experience in advertising and public relations. She is a member and past president of the Sioux City Growth Organization, Siouxland Chamber Ambassador, and a steering committee member of the Chris Larsen Park Riverfront Development Project.  Britney lives in Sioux City, Iowa with her husband, Bryce.


Mary Koster, Youth Services Director

Mary Koster has worked in a part time capacity for Siouxland CARES since 2005, first as Administrative Assistant and now as Youth Services Director.  Mary is responsible for coordinating activities and  communication with the members of the Sioux City Mayor’s Youth Commission.  She is also responsible for coordinating all aspects for Teen Court in Dakota County.  Her duties include coordinating sessions for defendants, case management, and also volunteer coordination for the 60 Teen Court volunteers.Mary is married to husband, Tom, has three children and four grandchildren.