National Geodetic Survey (NGS)
Continuous Operating Reference Stations (CORS)
Very Long Baseline Interferometry (VLBI)
Indiana Society of Profesional Land Surveyors (ISPLS)
Minnesota DOT HARN Site (Minnesota is the state with the most dense HARN)
Reporting Damaged and Destroyed NGS Stations
U.S. Army Corps of Engineers Topographic Engineering Center (CORPSCON may be obtained here)
Menror Software Forward/Inverse Program
High Precision Geodetic Network FTP Site (download inhpgn.las and inhpgn.los when available)