Lyon County Plat Books Countywide Directory, LLC produces an annual Lyon County Plat and Directory Book Lyon County has the 2007 plat books available for free. Visit the Auditor/Treasurer's office at the Government Center (Courthouse), or stop at the Public Works building. Please contact Mark Volz (507-532-8218) or Ryan Wendt (507-532-8212) if you'd like to have one mailed, postage is extra. Maps to Government Center: Mapquest | Yahoo Maps | Google Maps Maps to Public Works building: Mapquest | Yahoo Maps | Google Maps