© Chesapeake Bay Program (Chesapeake)

Chesapeake Bay: Forests


This map depicts the Chesapeake watershed’s most ecologically and economically important forests lands. Conserving the region’s forests is key to maintaining wildlife, drinking water supplies, air and water quality, recreation, tourism, timber sources, and economic sustainability.

Data Layer Description


Chesapeake Conservation Partnership


Pennsylvania, New York, Delaware, Maryland, Virginia, West Virginia, and the District of Columbia.


The map depicts important forest lands related to the Chesapeake Conservation Partnership long-term forest conservation goal: “Protect the Chesapeake watershed’s most ecologically and economically valuable forest land from conversion--headwater and riparian forests, large forest blocks, woodlots providing multiple values, and highly productive timber growing soils.”

This goal identifies four mappable categories. In each, forests are defined as areas with 50% or greater canopy coverage, as derived from the 30-meter resolution 2011 National Land Cover Dataset and resampled to 10 meter resolution. Where “contiguous” is used it means areas of forest connected by corridors at least 40 meters in width. The map was prepared in consultation with the CBP Forestry Work Group. These are the contributing forest categories:

Headwater and Riparian Forests: Headwater forests are defined as areas within National Hydrography Dataset Plus (NHD Plus) catchments that contain a NHD 100K scale first-order stream, are in the top half of elevation values within the Chesapeake Bay watershed, and are in contiguous blocks at least 50 acres in size. Riparian forests are areas within a 10 m buffer of NHD 100K streams.

Large Forest Blocks: These are blocks of contiguous forest 500 acres or larger.

Multiple Value Woodlots: These are blocks of contiguous forest at least 50 acres in size, but less than 500 acres.

Forests Conducive to Timber Harvests: These are defined as areas of harvestable contiguous forest blocks 500 acres or larger with less than 30% slopes.

This map depicts the concentration or overlapping of these forest values. Due to forest patch size criteria, Large Forest Blocks and Woodlots are mutually exclusive, as are Productive Timber Growing Areas and Woodlots. Therefore, although there are four input layers, the maximum value in the composite layer is three.  For instance, values of three could indicate overlap between Large Forest Blocks, Riparian/Headwater Forests, and Productive Timber Growing Areas. Woodlots can have a value of two only when they overlap with Riparian/Headwater Forests.

How to get the data layer

Contact Andy Fitch, Chesapeake Bay Program,  

How you might make use of this data layer

This dataset shares important forest lands for long-term conservation. This information may be useful in planning and supporting various collaborative conservation efforts.

How to get more information

For more information about the Chesapeake Conservation Partnership contact: John Griffin, Program Manager,

For more information about forests and forest conservation goals, contact: Sally Claggett, USDA Forest Service, 410-267-5706,

Access and use constraints

Attribution No Derivatives (BY-ND)


2017, Chesapeake Conservation Partnership and Chesapeake Bay Program.

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