Technical Abstract: An outbreak of the Desert Locust in the spring and summer of 2004 was the worst in the last 10 years and resulted in economically significant losses to both subsistence and export agriculture across areas of northern and western Africa. An analysis of rainfall and remotely sensed vegetation index measurements shows unusual rainfall in the summer of 2003 on the margins of the Sahara Desert was the triggering event. Subsequently, unusual rains in northwest Africa during the spring of 2004 resulted in continued favorable conditions for the large-scale locust reproduction and population expansion for several generations with subsequent desert locust outbreaks or plagues that affected large areas of Northwestern and Sahelian West Africa during 2004. Satellite remote sensing of both rainfall and developing green vegetation conditions can identify locations of initial and subsequent locust breeding for targeted ground surveillance and control. This information is critical to target areas of developing populations of desert locust for control campaigns.