Description: The National Hydrography Dataset (NHD) is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. NHD data was originally developed at 1:100,000-scale and exists at that scale for the whole country. This high-resolution NHD, generally developed at 1:24,000/1:12,000 scale, adds detail to the original 1:100,000-scale NHD. (Data for Alaska, Puerto Rico and the Virgin Islands was developed at high-resolution, not 1:100,000 scale.) Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. Reaches are also defined on waterbodies and the approximate shorelines of the Great Lakes, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee.
Description: This is an Arc/Info coverage consisting of 25 polygons representing currently proposed Research Natural Areas (RNAs) in Zion National Park, Utah. These RNAs are part of the Zion National Park General Management Plan (GMP), which are also referred to as the Visitor Management and Resource Protection Plan (VMRPP), and which designates 7 administrative zones to be managed appropriately. RNAs are specific areas of land to be used for the sole purpose of education and research. They have been selected and designated based on various criteria, and based on information gathered and analyzed from wildlife, vegetation, demographic, historic, and cultural databases.
Description: This is an Arc/Info coverage containing one polygon representing the boundary (current as of April 2002) of Zion National Park, Utah. This coverage is in NAD 83.