QQuakeFacts
QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/mb19250628020527000
USGS mb19250628020527000

28 Jun 1925, 03:05

Clarkston Valley, Montana (Aftershock)

A magnitude 6.4 mfa earthquake at 0 km depth.

Depth0 kmPublished hypocentral depth
Tsunami flagNot flaggedUSGS catalog flag, not a current warning
Updated15 June 2025Latest timestamp stored in this record

Published location

Where is Clarkston Valley, Montana (Aftershock)?

This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.

46.080000, -111.510000

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Map data © OpenStreetMap contributors

What the numbers mean

Magnitude measures event size; depth locates the source below the surface. Neither value alone establishes local damage or personal risk.

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Nearby events with a similar magnitude

M 6.3

22 km SW of Mammoth, Wyoming

M 6.6

The 1925 Clarkston Valley, Montana Earthquake

M 6.13

12 km N of Winston, Montana

M 6.1

30 km SSW of Big Sky, Montana

M 7.2

The 1959 Hebgen Lake, Montana Earthquake

M 5.3

29 km WSW of Freedom, Idaho

Catalog fields and provenance
Event ID
mb19250628020527000
Coordinates
46.08, -111.51
Network
mb
Significance
630