Spectral Mixture Analysis (SMA) was used to distinguish the fractional abundance of green foliage, dry grass, and soil in Airborne Visible Infrared Imaging Spectrometer (AVIRIS) data. Three maximum likelihood classifications were performed using topographic data only, SMA fractions only, and both topographic and SMA fractions. The predictions were compared to a field based vegetation map and to an aerial photograph of the scene. The combined data set produced the highest correspondence with the vegetation map for an overall correlation of 57 per cent for five classes. Part of the difference was attributed to misclassification in the field-based map.