Single relativistic-Maxwellian fits are made to high-latitude GPS-satellite observations of energetic elec-trons for the period January 2006–November 2010; a constel-lation of 12 GPS space vehicles provides the observations. The derived fit parameters (for energies ∼0.1–1.0 MeV), in combination with field-line mapping on the nightside of the magnetosphere, provide a survey of the energetic electron density and temperature distribution in the magnetotail be-tween McIlwain L-values of L = 6 and L = 22. Analysis reveals the characteristics of the density-temperature distri-bution of energetic electrons and its variation as a function of solar wind speed and the Kp index. The density-temperature characteristics of the magnetotail energetic electrons are very similar to those found in the outer electron radiation belt as measured at geosynchronous orbit. The energetic electron density in the magnetotail is much greater during increased geomagnetic activity and during fast solar wind. The total electron density in the magnetotail is found to be strongly correlated with solar wind speed and is at least a factor of two greater for high-speed solar wind (V SW = 500–1000 km s −1) compared to low-speed solar wind (V SW = 100–400 km s −1). These results have important implications for understanding (a) how the solar wind may modulate entry into the magne-tosphere during fast and slow solar wind, and (b) if the mag-netotail is a source or a sink for the outer electron radiation belt.