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We present new results from paleoseismic trenches excavated across the main trace of the Rose Canyon fault zone (RCFZ) in Old Town‐San Diego, California, to determine the timing of late‐Holocene earthquakes. There is evidence for four large surface‐rupturing events, as well as two smaller events, the youngest of which cuts the early historical living surface that contains glass, ceramics, and a historical era foundation. This youngest event is likely related to the 1862 San Diego earthquake, which had an estimated magnitude close to M 6. The age of older ruptures is constrained by 36 radiocarbon dates that exhibit good stratigraphic order. The four larger events produced substantially more ground deformation, and over a broader width of the fault zone, than the 1862 event. The youngest of the four larger events is found immediately below the historical horizon and likely correlates with the most recent event …