Free Maryland GIS Data Resources

It was with great interest that I read this post last week about the cost of GIS data in the Washington, DC region. Not only is the post itself informative but the comment discussion is also a worthy read.

This did get me curious, however, as to which counties in my home state of Maryland make GIS data freely available. The approach I took to this was simple: I did what any average county resident would probably do and went to each county’s web site looking for a link to a data download. If I didn’t find something in a few clicks, I went to Google (search term: {county name} md gis). If there was nothing there, I moved on. With that, here are the counties I found which provide free, downloadable GIS data:

Carroll County (2000 Orthos only)

Cecil County

Frederick County (requires registration)

Harford County

Howard County

St. Mary’s County

UPDATE: Additionally, data is available from the Maryland State Highway Administration (ESRI personal geodatabase)

I’m sure Maryland is not unique in the varying ways in which GIS data is distributed and the myriad ways local jurisdictions attempt cost recovery. These are difficult issues in the best of times and the current economic climate doesn’t make them any easier.

I only surveyed data that was available from the counties (and Baltimore City) directly. I did not delve into the many municipalities. Basically, the list above should not be interpreted as comprehensive but I hope it is useful to some.

  • http://wherewithal1.wordpress.com/ Terry

    I am suffering from serious State flag envy.

  • http://georube.wordpress.com georube

    I found http://www.marylandgis.net/find.jsp a good resource when I was writing a paper on crowdsourcing crab counts.

    While at the county level they might not be the greatest, but when you start getting into the Chesapeake bay watershed, you’d be amazed at the data you’d find from both Natural Resources Agencies, and Universities in both VA and MD.

    • http://twitter.com/billdollins Bill Dollins (@billdollins)

      Agreed. I also didn’t list the Maryland iMap system which has a lot of data behind an ArcWall but isn’t downloadable without some serious hacking by an intrepid Python programmer who is comfortable with the ArcGIS Server Feature Layer REST API.

  • http://twitter.com/polemic Hamish Campbell (@polemic)

    What’s the licensing on the data? I’ve had a quick look but can’t find any information. It seems crazy that agencies put so many resources into publishing data, but don’t provide the basic information needed to use it safely!

    • http://geobabble.wordpress.com/ Bill Dollins

      It can be all over the place. Some governments put it in the public domain because they realize they don’t have the resources to enforce a license. Others have a click-through license.