The data assembled in these files has been obtained and reformatted from a number of sources. Generally, Gdata1.txt USGS Open-File Report 00-193 Principal Facts for Gravity Stations in Vacinity of San Bernardino, Southern California, Megan Anderson, Carter Roberts, and Robert Jachens Gdata2.txt and Gdata3.txt USGS Open-File Report 93-217-A Principal Facts and Base Station Descriptions for Gravity Data Compiled for the Santa Ana 1-degree by 2-degree Quadrangle, California Gdata4.txt (note only Free Air and Bouguer)