The Rapid Data Delivery System (RDDS) (formerly called 'Fire Data Ordering') from the USGS is an interactive web based GIS tool useful for downloading the DEM files required for use in WindNinja and WindWizard. The tool allows users to zoom into the desired area and extract a seamless DEM file in the correct format (ASCII Raster). A brief set of instructions describing the DEM extraction and download process is given below. More detailed instructions can be found on the RDDS web page under 'Help' on the left hand side of the page.