Long wavelength anomalies in the total magnetic field measured by Magsat over the United States and adjacent areas are inverted to an equivalent layer crustal magnetization distribution. The model is based on an equal area dipole grid at the Earth's surface. Model resolution, defined as the closest dipole spacing giving a solution having physical significance, is about 220 km for Magsat data in the elevation range 300--500 km. The magnetization contours correlate well with large-scale tectonic provinces.