This paper highlights a three-dimensional (3-D) transient numerical simulation of the Baneberry event of December 18, 1970, with a 10-kT yield and a 278-m source depth, conducted at the Nevada Test Site. This site has complex geological features with preexisting faults and layered geological strata characterized by a hard Paleozoic layer below the source, and saturated tuff on the west side of the source and clay-rich tuff toward the east side, both overlaid by top alluvial layers. In addition, a layer of 50% montmorillonite is sandwiched between two layers of 20% montmorillonite on the east end. This event is reported to have vented because of fault rupture and shock-wave reflections from a closer hard Paleozoic layer near the source. Here, the shock-induced slip along the preexisting fault plane has an important bearing on the containment efficiency of this event. None of the earlier reported simulation studies …