The June 29, 1992, mb=5.5, Little Skull Mountain earthquake occurred 20 km southeast of Yucca Mountain within the boundaries of the Nevada Test Site. This event was recorded at a very broadband station located about 310 km to the east at Kanab, Utah. Both body and surface waves from this single station were used in a grid search technique for the best fitting double couple moment tensor. The technique minimizes the misfit between reflectivity generated complete synthetic seismograms and the three-component displacement data via a search over the strike, dip and rake of the source. In the passband of 50--15 s period, the grid search results in a well defined, nearly pure normal mechanism with a strike of 35¿, a dip of 54¿, a rake of -87¿, and a seismic moment of 4.1¿1017 N-m. Applying the same technique to the large aftershock on July 5, 1992 we obtain a somewhat less well defined minimum with a strike of 358¿, a dip of 36¿, a rake of -177¿, and a moment of 4.3¿1015 N-m. The minimum-compression axes of these mechanisms are consistent with northwest-southeast extension in the Basin and Range. ¿ American Geophysical Union 1993