Significant earthquakes of 1983

October 28, 1983 Earthquake: Borah Peak, Challis, Mackay, Idaho, United States

October 28, 1983 · M7.3 · 2 deaths · $12.5 million

A magnitude 7.3 earthquake struck Borah Peak, Challis, Mackay, Idaho, United States on October 28, 1983 at 14:06:06 UTC, 14 km below the surface. It killed 2 people.

Map

Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.

The earthquake

Date
October 28, 1983
Time
14:06:06 UTC
Place
Borah Peak, Challis, Mackay, Idaho, United States
Magnitude
7.3 (Ms)
Focal depth
14 km (9 mi)
Intensity
9 on the Modified Mercalli scale
Tsunami
None recorded
Epicenter
43.974° N, 113.916° W

The toll

Deaths
2
Injuries
2
Damage
$12.5 million

Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.

What the record says

NCEI’s account, from the sources it cites.

Reference #1250 lists $25 million damage.

Photos

From the NCEI/WDS Natural Hazards Image Database (doi:10.7289/V5154F01). Only photos by the USGS and NOAA, which are public domain, are shown.

Fault scarp caused by Borah Peak, Idaho earthquake
Fault scarp caused by Borah Peak, Idaho earthquake This section of the normal fault scarp was produced by the earthquake. It is 678.8 m northwest of the alluvial fan head on Rock Creek. Nearly vertical slickensides on the fault surface are visible on the lower half of the scarp. The scarp is 2.5 m high at this location. The earthquake killed two children in Challis, Idaho, and caused $12.5 million in… Photo: R.C. Bucknam, U.S. Geological Survey.
Fault scarp and horizontal offset near Dickey, Idaho
Fault scarp and horizontal offset near Dickey, Idaho The scarp and fracture zone are located on Rock Creek, near Dickey, Idaho, and Double Springs Pass Road. The wooden pole is 1.9 m high. This normal fault shows characteristics of oblique-slip, where there is both vertical and horizontal displacement. The horizontal movement is left-lateral. The fault scarp extended for more than 35 km, with vertical… Photo: G. Reagor, U.S. Geological Survey.

Other significant earthquakes nearby

Within 200 km, the deadliest first.

More

Significant earthquakes of 1983The 1900sEvery quake the USGS located in 1983Recent earthquakes near hereThis day in weather history

Sources

Significant earthquakes from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI earthquake 5677.