Publication of 1:25,000-scale US Topo maps in Alaska began in July 2013. The production schedule is determined by availability of IFSAR elevation data and SPOT imagery provided by the Alaska Statewide Digital Mapping Initiative. About 1,100 maps were published in 2013 and 2014. Larger numbers are expected in the next few years due to increasingly complete coverage of image and elevation data. More than 11,000 maps will be required to cover the state, and full coverage is not expected until at least 2018.