The 1925 Montana (Clarkston Valley) earthquake occurred at 17:21:12 MDT on 27 June in Montana, with the epicenter being located near Townsend. The earthquake had a magnitude of 6.9 in the surface wave magnitude scale. A maximum intensity of IX (Violent) was observed. Serious damage was reported near the epicenter. 3 hours after the mainshock, a strong aftershock was recorded with an unknown magnitude that also caused damage.