NPScape population metrics are calculated using data from the US Census Bureau. Metric GIS datasets are produced seamlessly for the United States, although both geographic coverage and resolution vary by time period (historic, current, and projected future). The methods underlying these calculations are available for download through the NPScape website: http://science.nature.nps.gov/im/monitor/npscape/methods.cfm. In an analytical context, NPScape population data are provided in two forms: (1) tool input data, for use in replicating NPScape methods, and (2) metric output data, for users wishing to map and further analyze metrics.
