Top surface DEMs by USGS quarter quad In this directory you can access all 3-ft Top Surface .e00 files that are in UTM Zone 11 N, NAD83 HARN, meter horizontal units, NAVD88 vertical Datum and meters vertical units. You can download index files here: http://pugetsoundlidar.ess.washington.edu/lidardata/indexfiles.html If you have any questions or need help contact Diana Martinez at dmartinez@psrc.org