Listers, Thanks to everyone who replied - I'm making some progress, but have hit another bump. BTW, here's the complete URL for one of the maps I'm working on: http://wrgis.wr.usgs.gov/open-file/of95-699/ First, thanks to Matt Wilkie who determined that despite the downloaded files retaining their .gz extension, they were not actually compressed! According to Matt, "The reason is some servers are setup to automatically uncompress gzipped files on normal requests." I just trimmed off the .gz extension, leaving the files with the .e00 extension of an ArcInfo export file. Here's where the new wrinkle comes in - the accompanying USGS text file describes the projection as follows: The map databases consist of ARC coverages which are stored in State Plane (California coordinate system) projection (Table 1). Digital tics define a 2.5 minute grid of latitude and longitude in the geologic coverages corresponding with quadrangle corners and internal tics. In the base map layer, the tics define a 7.5 minute grid, corresponding with quadrangle corners. Table 1 - Map Projection The map is stored in State Plane projection PROJECTION STATE PLANE UNITS METERS -on the ground ZONE 3426 -Arc/Info State Plane zone corresponding to California coordinate system zone 7 DATUM NAD27 PARAMETERS -none This seems to be a custom projection, since the unit of measure in the State Plane Coordinate System is the Survey Foot. ArcLink opens these files perfectly, but because the default setting in MI for units in NAD27 SPCS is survey feet, the files aren't projected correctly. I know I can edit the MI projection file to create a custom projection, but will ArcLink recognize the custom projection and import the file properly? Thanks again to everyone. Cheers, Tim _____________________________ Tim Warman Geologist & GIS Specialist Richard C. Slade & Associates North Hollywood, CA (818) 506-0418 ---------------------------------------------------------------------- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
