In 1979 the University of Minnesota Mobile Laboratory (UMML), designed for the analysis of airborne particles and gases, was used to study fugitive dust from an open pit coal mine. The analysis consisted of determining the particle size distribution and concentration of dust from various mining operations such as blasting, draglines, loading, roadways, and bottom scrapers. For some operations the particles size distribution and concentrations were determined at varying distances. Details of the dust concentration within the plumes as the plume passed the UMML were measured with an optical particle counter. For line sources, such as roadways, these measurements enabled the calculation of the particle flux at the sampling location. In addition to the standard instruments associated with the UMML, the applicability of some new instruments was investigated. These included a uniform deposit cascade impactor and a flux meter. Finally, a technique in identifying plume origins that utilize elemental x-ray fluorescence analysis of filter samples was shown to be effective.