This report is a compilation of input and output measures and other statistics in reference to Idaho's public libraries, covering the period from October 1997 through September 1998. The introductory sections include notes on the statistics, definitions of performance measures, Idaho public library rankings for fiscal year 1996, and a state map showing the locations of Idaho public libraries. The statistical data are divided into three tables: (1) libraries by county, including data on population, registered borrowers, facilities, staff, directors, operating income, operating expenditures, collections, hours and use of the library, circulation, and interlibrary loans; (2) libraries by population served, including the same data elements as the first table; and (3) public libraries by name with city, county, NUC (National Union Catalog) symbol, foundation, friends, audits, and long range plan years. Four graphs provide 1994-98 data on population, attendance, circulation, and expenditures, and a public library statewide summary for 1994-98 is included. The final section of the document is an Idaho public library directory. (MES)