The North American Monsoon Experiment (NAME) was held over southwestern North America during the summer of 2004 with the aim of improving forecasts of rainfall over the region. One focus of the NAME was to improve the understanding of the precipitation around the Gulf of California. Over this region the maximum rainfall occurs close to the western slopes of the Sierra Madre Occidental mountains early in the wet season, but moves towards the coastal region and over the Gulf of California as the rainy season progresses. This westward tendency may be due to seasonal changes in the land-sea temperature contrast. A special network of observations was designed to evaluate the possible effects of rainfall, vegetation cover change, and sea surface temperature change throughout the warm season in contributing to the observed rainfall migration. This talk will provide an overview of the observational program, including the special sounding and surface measurements that were made. A preliminary assessment of the data set and some implications will be presented.