© Chesapeake Bay Program (Chesapeake)

High Value Forests


These map layers show high value forests for water quality, as identified by Maryland, Virginia, and Pennsylvania forestry agencies for the 2007 Forest Conservation Directive signed by the Chesapeake Executive Council. In this Directive, the Bay States committed to permanently protect an additional 695,000 acres of forest by 2020, focusing on these priority high value forests.

Data Layer Description


Data layers compiled by USDA Forest Service (USFS)/Chesapeake Bay Program from State forestry agencies in Maryland, Pennsylvania, and Virginia.


Chesapeake Bay watershed  (MD, VA, PA only)


In 2007, as part of the Chesapeake Forest Conservation Directive, the six Bay States committed to collectively protect an additional 695,000 acres of forest from conversion by 2020, targeting forests in areas of highest value to water quality.  Maryland, Virginia, and Pennsylvania conducted GIS analyses to identify high priority forest land for conservation.

In this analysis, Virginia overlaid multiple GIS data layers to develop a 12 point ranking scale from lowest to highest priority (see detailed VA Methodology). The highest value forests shown in red in Virginia’s map layer correspond to the forests ranked highest (10-12) on the scale. Virginia incorporated a vulnerability to development layer into their high value forest ranking.

Maryland also used a ranking scale that incorporated a variety of GIS data layers, with associated weights given to each layer (see MD Methodology chart). The highest value forests shown in red in Maryland’s map layer correspond to the top 50% of forests on the ranking scale.

Pennsylvania updated their priority forest map in 2010 as part of the State Forest Resource Assessment.The highest value forest shown is a composite of multiple forest priority layers (see PA Methodology).

States in the headwaters - West Virginia, Delaware, and New York – can use the Water Quality Protection data layer from the Chesapeake Resource Lands Assessment to identify high value forests for water quality, until they have developed their own maps.

How to get the data layer

Contact Julie Mawhorter, USFS, Chesapeake Bay Program (410-267-5708)

How you might make use of this data layer

The map layers can be used to target forest conservation efforts to landowners of high value forests, to maximize water quality benefits to the Chesapeake Bay watershed. It is important to note that the high value forests shown do include some areas that are already protected as public lands or through private easements, especially in Pennsylvania where much of the high value forests occur on state-owned conservation lands. To use these layers for targeting, it is recommended to overlay (display) the Chesapeake Bay Program Protected Lands 2011 layer and focus on the high value forests not already protected.

How to get more information

To learn more about the importance and status of forest land in the Chesapeake Bay watershed, refer to the 2006 State of Chesapeake Forests report. One funding source for protecting high priority private forest land is the USFS Forest Legacy Program, which is delivered by State forestry agencies.

Access and use constraints

All Rights Reserved


Chesapeake high value forests map layers were compiled from State forestry agencies by the USFS/Chesapeake Bay Program for the 2007 Forest Conservation Directive.

Sample Map

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