A Digital Line Graph (DLG) is digital vector data representing cartographic information. DLGs contain a wide variety of information depicting geographic features (for example, hypsography, hydrography, boundaries, roads, utility lines, etc). DLGs are derived from hypsographic data (contour lines) using USGS 7.5-minute, 15-minute, 2-arc-second (30- by 60-minute), and 1:2 million-scale topographic quadrangle maps.
Crater Lake National Park covers twelve 7.5-minute quadrangle maps. These 12 DLG quads have been mosaicked together. The mosaicked files are more convenient for looking at areas throughout the basin or areas on the edge of two quadrangles.
DLGs are in UTM NAD27 zone 10 projection.