Digital Maps Online	contact:jim Reger (jreger@mgs.md.gov)

     We are currently developing online maps for the Chesapeake Bay and Atlantic Coast in Maryland. Three types of maps are available: raster (bitmap) images, vector graphics and interactive maps. Raster images should be viewed and printed using the resolution at which they were created. Magnifying a raster distorts the image.
      Vector graphics can be rescaled without distortion, but require software which can read vector graphic data files. Interactive maps are vector objects that may be viewed on the World Wide Web at any resolution. The user may zoom in and out of the vector image, and print the image to any desired scale. These vector objects are a interactive - the user can activate various layers of data, pan and zoom the image, and read coordinates from the image.
     Raster maps can be viewed through your web browser without any special plug-ins. Vector graphics can be downloaded for use with your own software. The interactive maps presented on the MGS web pages require a special browser plug-in. Information on this plug-in is found on MGS's VMAP page.

PLEASE NOTE: Do not use these documents for navigation, legal purposes, surveying, or anything else other than document illustrations. They were created only to illustrate our publications and are not accurate enough to be used for any other purposes. You may use them as illustrations only, and you must give proper credit to Maryland Geological Survey when using these maps.

Online Map Series PLEASE NOTE: Do not use these documents for navigation, legal purposes, surveying, or anything else other than document illustrations. They were created only to illustrate our publications and are not accurate enough to be used for any other purposes. You may use them as illustrations only, and you must give proper credit to Maryland Geological Survey when using these maps.			Formats
			Bitmap	PDF	Interactive	Data
Geologic Map Series
	Index to Geologic Maps of Maryland	Detailed Geology of Maryland presented county-by-county.
		Geologic cross-sections of the entire state
		Geology of the Great Falls gold district (1953)
	Generalized Geological Map of Maryland	A generalized map suitable for printing (PDF)
	Physiographic Provinces of Maryland (2001)	The six Maryland physiographic provinces
	Geology of the C & O Canal Park and Vicinity	Geology of the popular park
	Chesapeake Bay Sediment Distribution	Map of the distribution of Chesapeake Bay surficial sediments.  Interactive map requires browser plugin.
	Baltimore Harbor Surficial Sediments: Texture, Water Content, Carbon, Nitrogen and Sulfur	Map of the distribution of Baltimore Harbor surficial sediments.  Interactive map requires browser plugin.
	Atlas of Maryland's Coastal Bays: Physical & Chemical Characteristics	Map of Coastal Bays surficial sediments. Interactive map requires browser plugin.
Shoreline Maps
	High-Resolution Shoreline Map Data for Tidewater Maryland	GIS data  for use in  AutoCAD, ArcGIS, etc.
	Shoreline Change Map Data for Tidewater Maryland	GIS data  for use in  AutoCAD, ArcGIS, etc.
	Chesapeake Bay shorelines, in raster (GIF, TIFF , etc.) images and vector (DXF) data formats	Small-scale, entire bay, 351 x 549 pixels, (7.11 kb)
		Small-scale, tidewater MD bay only, 201 x 265 pixels, (2.83 kb)
		Large-scale, MD-VA bay, 3241 x 4977 pixels,  600dpi, grey scale TIFF fomat.  Prints to 8.3" x 5.4" at 600dpi (305 kb). Download and unzip.
		Large-scale, tidewater MD bay only, 487 x 631 pixels, (9.83 kb)
	Atlantic Coast shorelines, in raster (GIF) images and vector (DXF) data formats	Small-scale, coast, coastal bays and streams, 333 x 542 pixels, (8.63 kb)
		Small-scale, Ocean City, coastal bays and streams, 375 x 463 pixels, (6.11 kb)
	Detail of "Shoreline Changes: Tilghman, MD"	Interactive map requires browser plugin.
Bathymetric Maps
	Reservoir Bathymetric Maps	Water depth map of Loch Raven Reservoir
		Water depth map of Prettyboy Reservoir
		Water depth map of Liberty Reservoir (in preparation, not yet available)
	Chesapeake Bay Map Data for GIS	Deepest Chesapeake Bay Channels in ESRI shape file format
Boundary Maps
	County boundaries, small-scale, no county names	932 x 502 pixels (12.5 kb)
	County boundaries, small-scale, with county names	952 x 549 pixels (16.6 kb)
	County boundaries, large-scale, no names	306 x 167 pixels, (3.19 kb)
	County boundaries, high-resolution GIS data format	ESRI .shp  and Autodesk .dxf formats
	Individual Maryland County Outlines	Both bitmaps and vector (dxf) data are available

SOURCES FOR TOPOGRAPHIC and OTHER ONLINE MAPS

Maryland Mapping Resource Guide (MMRG) If you are looking for on-line maps of Maryland, including USGS topographic maps, orthophotoquads, satellite imagery, place names, and other spatial data, visit the Department of Natural Resources' MERLIN, (Maryland 's Environmental Resources & Land Information Network) at http://www.mdmerlin.net/. With MERLIN you can tailor maps to suit your needs. Maps from Maryland State Archives Maryland Department of Planning MDMaps National Elevation Data Set (NED), National Atlas Data Set from the USGS Seamless Data Distribution System (SDDS) Visit USGS's National Geologic Map Database, where you can find information about maps and related data for geology, hazards, earth resources, geophysics, geochemistry, geochronology, paleontology, and marine geology. For free, online topographic maps try Topozone at http://www.topozone.com Look at USGS's National Hydrography Dataset for spatial data about surface water features such as lakes, ponds, streams, rivers, springs and wells. Maptech's Historical Map catalog has many interesting and old Maryland Maps Perry-Castañeda Library Map Collection (University of Texas) Recent Maps of Maryland University of Alabama's Historical Map Archive