All events occurred north of the Tintina fault, a strike-slip structure striking SE-NW. The source parameters of the mainshock and larger aftershocks from waveform modeling indicate strike-slip faulting, either left-lateral on a NE-striking focal plane or right-lateral on a SE-striking plane. The latter is consistent with the sense of motion along the Tintina fault. The former is similar to the NNE-trending seismic zones located farther south between the Denali and Tintina faults. A M4.5 aftershock later in the sequence has a normal faulting focal mehcanism, consistent with faulting on the NE-striking plane. Therefore, the NE-striking focal plane is a more likely fault plane of this sequence.