Technical Abstract: Leafy spurge, Euphorbia esula L. is an adventive, perennial weed that infests approximately 1.2 million hectares of land in North America. It often forms dense stands that displace native vegetation and useful forage plants on rangelands and in riparian habitats. One of the fundamental needs in leafy spurge management is cost-effective, large-scale, and long term documentation and monitoring of plant populations. Using remotely sensed data to map leafy spurge would provide a valuable tool for documenting leafy spurge distribution and infestation levels over larger regional areas. Leafy spurge is a good candidate for detection via remote sensing because the distinctive yellow-green color of its bracts is spectrally unique when compared to co-occurring green vegetation. During 1999, Airborne Visible / Infrared Imaging Spectrometer (AVIRIS) imagery was acquired in northeastern Wyoming and ground vegetation data was collected. Mixture Tuned Matched Filtering (MTMF), a specialized type of spectral mixture analysis, was used to estimate leafy spurge canopy cover and map leafy spurge distribution. Overall performance of MTMF for estimating percent cover of leafy spurge for all sites was good (r2 = 0.69) with better performance in prairie areas (r2 = 0.79) and poorer performance occurring on wooded sites (r2 = 0.57). The techniques presented here could possibly be used for constructing leafy spurge distribution and abundance maps with satellite hyperspectral data for larger regional areas.