Bill Ptacek, director of the King County Library System since 1989, has resigned, effective Feb. 1, 2014, to become CEO of the Calgary Public Library in Alberta, Canada.

During his 25-year tenure, Ptacek’s vision for technology and collection management kept the library system in the forefront of public libraries nationally. In 1990, it operated 36 community libraries with an annual circulation above nine million items. Under Ptacek , it grew as King County’s population and economy expanded and local municipalities voted to join the library system.

Voter-approved capital improvement bond measures (passed in 1988 and 2004) funded new, replacement and expanded libraries, adding nearly 515,000 square feet of library space, while annual circulation grew to more than 22 million items. Voters also passed a one-year levy increase during the 2009 economic crisis, demonstrating the community’s support of the system.

The library system typically shares one of the top three spots for highest circulating public library in the United States and leads the U.S., Canada and Australia in eBook circulation. It was named Busiest Library in 2010 and Library Journal’s 2011 Library of the Year.

“For Bill, this is a great opportunity to take on exciting new challenges…and it’s not easy to top the challenges Bill has tackled with KCLS. We are sorry to see him go,” said KCLS Board Chair Lucy Krakowiak.

Added board trustee Jessica Bonebright, “Bill’s move marks the beginning of our search for a candidate who can fill his well-worn running shoes. KCLS’ recruiting campaign for a new library director — a job opening rarely seen — will be conducted both nationally and internationally.”

Julie Brand, director of community relations and marketing, has been appointed to serve as interim director until a new director is hired.