The LAS data in this directory has been compressed using LASzip software. LASzip is an open source lossless compression for lidar point cloud data in the LAS format that provides significant file size reductions, helpful when downloading or storing large datasets. To uncompress the .laz files you can use the laszip.exe tool in this directory or you can download the latest version from the link below. http://www.cs.unc.edu/~isenburg/lastools/ See the laszip_README.txt in this directory to learn how to use the tool in the command line. Alternitably, in Windows Explorer you can also 'drag and drop' indiviual or muliple .laz files onto laszip.exe. This will automatically uncompress the files into the current directory.