Sonali Tiwary
A magnitude 3.6 earthquake rattled the area northwest of Black Eagle, near Great Falls, Montana, early Friday morning. The U.S. Geological Survey recorded the event at 7:40 a.m. local time on September 18, 2026. No injuries, serious property damage, or infrastructure disruptions have been reported.
Location and size
The epicentre was 5 km northwest of Black Eagle, at a depth of 27.731 km, according to the USGS event record `us7000tiax`. At magnitude 3.6, the quake falls in the "minor" category — strong enough to be felt by people near the epicentre, but not typically associated with significant structural damage.
Residents should check local emergency services and the USGS earthquake page for any revisions to the magnitude, depth, or aftershock assessments as the data is refined in the hours after the event.
Part of a longer sequence
KRTV reported that Friday's quake is likely another aftershock in a sequence that began with a magnitude 4.2 earthquake near the same area on January 29, 2026. That event was followed by shocks measuring 2.7, 3.2, 3.7, and 2.8 before Friday's 3.6. Aftershock sequences can continue for weeks or months after a main event, typically decreasing in frequency and size over time, though smaller aftershocks at this magnitude are possible.
No formal determination from the USGS on whether Friday's quake is officially classified as part of that sequence had been issued at time of publication.
The USGS will update its event record as seismic data is refined. Local emergency officials remain the most reliable source if you have damage to report or safety concerns. Check the USGS earthquake hazards page for the latest readings from this area.
