Explains how the NHD specifies point locations within streams by using a code to indicate the reach (including the hydrologic unit) and a measure, which indicates how far the point is from the downstream end of the reach.
Portal to general information on the National Atlas of the United States with access for producing specialized maps and links to thematic maps including interactive maps, multimedia maps, map layers data warehouse, wall maps, and printable maps.
Shows where current natural hazard events are occurring within the US or worldwide, with information about the geographic extent of the hazard, the US agency engaged to work on it, and how long the hazard is expected be active.
Information on the Gap Analysis Program in Ohio, a geographic approach to planning for biological diversity by mapping native aquatic and terrestrial animal species and natural communities on present-day conservation lands.
Brief summaries of USGS projects in Texas including water quality monitoring, digital mapping, energy resources, U.S.-Mexico border mapping, fish and wildlife health, Kemp's Ridley sea turtle, and conditions affecting water quality.
Site for the Optical Science Laboratory specializing in expert calibration of aerial mapping cameras with links to fees, scheduling cameras for calibration, historical camera database files, USGS aerial camera specifications, and how to visit.
Site to learn about, view, and order digital image vegetation condition (greenness) maps of the conterminous U.S. based on the Normalized Difference Vegetation Index (NDVI) with imagery from Advanced High Resolution Radiometer (AVHRR).