country List of the highest major summits of North America Normalhöhennull, German vertical datum, literally: standard elevation zero, (NHN) North American Vertical Datum of 1988, (NAVD 88) Sea Level Datum of 1929, a superseded United States vertical datum, (NGVD 29) Orthometric height Physical geography Topographic isolation Topographic prominence Topography Vertical pressure variation References External links U.S. National Geodetic Survey website Geodetic Glossary @ NGS NGVD 29 to NAVD 88 online elevation converter @ NGS United States Geological Survey website Geographical Survey Institute Downloadable ETOPO2 Raw Data Database (2 minute grid) Downloadable ETOPO5 Raw Data Database (5 minute grid) Find the elevation of any place Geodesy Topography Physical geography Surveying Mountaineering Vertical position