The U.S. Climate Reference Network (USCRN) is a network of 114 stations developed, deployed, managed, and maintained by the National Oceanic and Atmospheric Administration's (NOAA) National Climatic Data Center (NCDC) in the continental United States for the express purpose of detecting the national signal of climate change. The USCRN program began fielding stations in 2001, and the vision of the program is to maintain a sustainable high-quality climate observation network that 50 years from now can with the highest degree of confidence answer the question: How has the climate of the nation changed over the past 50 years? These stations were designed with climate science in mind. Three independent measurements of temperature and precipitation are made at each station, insuring continuity of record and maintenance of well-calibrated and highly accurate observations. The stations are placed in pristine environments expected to be free of development for many decades. Stations are monitored and maintained to high standards, and are calibrated on an annual basis. In addition to measurements of surface temperature and precipitation, these stations also measure solar radiation, surface skin temperature, and surface winds. Since 2009 the network has been augmented by the implementation of triplicate measurements of soil moisture and soil temperature at five depths, as well the installation of atmospheric relative humidity sensors. Experimental stations have been located in Alaska since 2002 and Hawaii since 2005, providing network experience in polar and tropical regions; furthermore, as part of the most recent International Polar Year and in partnership with Roshydromet (the Russian Federation's Federal Service For Hydrometeorology and Environmental Monitoring), a USCRN station was installed in Tiksi in the Russian Arctic to help further advance the need for reference surface climate observations in high latitude regions. Deployment of a complete 29 station USCRN network into Alaska began in 2009. While the network is managed by NOAA/NCDC, the on-going operation and continuous improvements in the system would not be possible without the work done in partnership with NOAA's Atmospheric Turbulence and Diffusion Division. Data from all stations in addition to all system documentation is available from the USCRN website at http://www.ncdc.noaa.gov/crn/.