|Map data are available from the Ohio Geological Survey over the Internet through the Survey's Anonymous FTP Site. To access data at this site, please use the following instructions:
- If you are using Netscape, Internet Explorer, or any other Web browser, the URL is ftp://ftp.dnr.state.oh.us/Geological_Survey/.
- On this site you will find the following subdirectories:
- Choose a directory by clicking on it.
- Within the appropriate directory locate the file(s) you wish to download. Select by right-clicking on it. Save the file(s) to a directory of your choice on your local hard drive.
Some of these files may be very large. If you are connected to the Internet via a relatively slow speed modem, it may require an extremely long time to download the files. If you are paying long-distance connection charges, you may want to consider ordering the files from the Division of Geological Survey on magnetic media.
All graphics files are in AUTOCAD-compatible drawing file (.DWG) format. Each file contains graphics for one specific county. The file-naming convention used for the graphics files uses the first three letters of the county name, then a type identifier (if a road file) and lastly a coordinate zone indicator. Thus file ERI_SPN.DWG = Erie County base-map file in state plane coordinates, North zone. File ERIRTE_SPN.DWG = Erie County roads file in state plane coordinates, North zone.