1909 05 16 04:15 UTC (Local 05/15)
Largest Earthquake in North Dakota
This moderate earthquake was felt widely over south-central Canada and the north-central United States, including the States of Montana and North Dakota. A retaining wall fell in Helena, southern Lewis and Clark County, Montana; plaster was cracked at Havre (northwest of Helena, in Hill County). The shock also was "severe" in Dickinson (Stark County), North Dakota. Some windows were broken and articles fell from shevles at a few towns in Saskatchewan, Canada.
Abridged from Seismicity of the United States, 1568-1989 (Revised), by Carl W. Stover and Jerry L. Coffman, U.S. Geological Survey Professional Paper 1527, United States Government Printing Office, Washington: 1993.