M1.8 earthquake 28 km S of Mammoth, Wyoming

Magnitude

1.8 (ML, local (Richter)), micro

Magnitude from

University of Utah Seismograph Stations

Local time

Thu, Dec 9, 2021, 1:56 AM MST

UTC

2021-12-09 08:56:19 UTC

Depth

4.2 km (2.6 mi), shallow

Epicenter

44.721° N, 110.678° W

Region

Montana

Tsunami flag

No

Status

Reviewed by a seismologist

Location uncertainty

About 0.7 km horizontally, 0.3 km in depth

Magnitude uncertainty

±0.11

Depth from

From location

Station coverage gap

152°

Stations used

12

• West Yellowstone, MontanaPopulation 1,339. Forecast34 kmE
• Bozeman, MontanaPopulation 43,405. Forecast110 kmSSE
• Billings, MontanaPopulation 117,116. Forecast207 kmSW
• Calgary, CanadaPopulation 1,306,784. Forecast748 kmSSE

After

1. 2.635 km S of Silver Gate, MontanaSat, Dec 18, 2:12 PM MST · 1751 days ago · 15 km deep · 54 km away
2. 1.523 km W of Hebgen Lake Estates, MontanaTue, Dec 21, 7:00 PM MST · 1748 days ago · 11 km deep · 65 km away
3. 2.566 km NNE of Kelly, WyomingFri, Dec 24, 12:41 AM MST · 1746 days ago · 11 km deep · 71 km away
4. 1.966 km NNE of Kelly, WyomingMon, Dec 27, 7:36 AM MST · 1743 days ago · 13 km deep · 71 km away
5. 1.634 km ESE of West Yellowstone, MontanaMon, Dec 27, 8:50 PM MST · 1742 days ago · 6 km deep · 17 km away
6. 1.620 km ENE of Hebgen Lake Estates, MontanaMon, Dec 27, 10:35 PM MST · 1742 days ago · 6 km deep · 23 km away
7. 2.366 km NNE of Kelly, WyomingSat, Jan 1, 12:36 AM MST · 1738 days ago · 11 km deep · 71 km away
8. 1.617 km SSE of Big Sky, MontanaSat, Jan 1, 5:19 PM MST · 1737 days ago · 5 km deep · 67 km away
9. 1.743 km ESE of West Yellowstone, MontanaWed, Jan 5, 12:39 PM MST · 1733 days ago · 3 km deep · 24 km away
10. 2.522 km SSW of Mammoth, WyomingWed, Jan 5, 6:43 PM MST · 1733 days ago · 8 km deep · 13 km away
11. 1.623 km SSW of Mammoth, WyomingSun, Jan 9, 2:40 AM MST · 1730 days ago · 7 km deep · 13 km away
12. 2.122 km SSW of Mammoth, WyomingWed, Jan 12, 9:58 AM MST · 1726 days ago · 9 km deep · 14 km away · felt by 1
13. 2.041 km SSW of Silver Gate, MontanaWed, Jan 12, 10:58 AM MST · 1726 days ago · 4 km deep · 43 km away
14. 2.726 km SSE of Virginia City, MontanaWed, Jan 19, 12:21 PM MST · 1719 days ago · 10 km deep · 100 km away
15. 2.361 km SSE of Mammoth, WyomingFri, Jan 28, 2:44 PM MST · 1710 days ago · 0 km deep · 38 km away
16. 1.539 km WNW of Cody, WyomingTue, Feb 1, 5:32 AM MST · 1707 days ago · 9 km deep · 92 km away
17. 1.842 km W of Hebgen Lake Estates, MontanaSat, Feb 5, 5:05 AM MST · 1703 days ago · 9 km deep · 83 km away

Before

1. 1.7WyomingMon, Dec 6, 7:43 AM MST · 1764 days ago · 13 km deep · 54 km away
2. 1.619 km ENE of West Yellowstone, MontanaSun, Dec 5, 4:01 PM MST · 1764 days ago · 8 km deep · 16 km away
3. 1.922 km SSW of Mammoth, WyomingWed, Dec 1, 5:15 AM MST · 1769 days ago · 4 km deep · 12 km away
4. 1.946 km ESE of West Yellowstone, MontanaMon, Nov 29, 4:13 PM MST · 1770 days ago · 7 km deep · 23 km away
5. 2.419 km NE of West Yellowstone, MontanaSun, Nov 28, 5:00 PM MST · 1771 days ago · 8 km deep · 21 km away
6. 1.939 km ESE of West Yellowstone, MontanaSat, Nov 27, 2:00 AM MST · 1773 days ago · 7 km deep · 18 km away
7. 1.830 km ESE of West Yellowstone, MontanaFri, Nov 26, 8:00 AM MST · 1774 days ago · 8 km deep · 15 km away
8. 1.829 km S of Mammoth, WyomingMon, Nov 22, 10:06 AM MST · 1777 days ago · 5 km deep · 1 km away
9. 1.928 km S of Mammoth, WyomingSun, Nov 21, 1:23 AM MST · 1779 days ago · 4 km deep · 0 km away
10. 1.950 km SSE of Mammoth, WyomingTue, Nov 16, 5:31 AM MST · 1784 days ago · 2 km deep · 27 km away
11. 1.846 km NE of Alta, WyomingSat, Nov 13, 12:03 AM MST · 1787 days ago · 10 km deep · 71 km away
12. 1.727 km S of Mammoth, WyomingFri, Nov 12, 6:45 AM MST · 1788 days ago · 4 km deep · 1 km away
13. 1.6WyomingWed, Nov 10, 9:09 PM MST · 1789 days ago · 9 km deep · 44 km away
14. 1.540 km SSE of West Yellowstone, MontanaWed, Nov 10, 9:07 PM MST · 1789 days ago · 2 km deep · 43 km away
15. 2.246 km NE of Alta, WyomingWed, Nov 10, 6:15 AM MST · 1790 days ago · 7 km deep · 72 km away
16. 2.546 km NE of Alta, WyomingWed, Nov 10, 5:56 AM MST · 1790 days ago · 10 km deep · 71 km away · felt by 1
17. 1.621 km ENE of Hebgen Lake Estates, MontanaTue, Nov 9, 11:51 AM MST · 1790 days ago · 7 km deep · 26 km away
18. 1.526 km W of Hebgen Lake Estates, MontanaTue, Nov 9, 9:06 AM MST · 1790 days ago · 13 km deep · 67 km away

From the USGS Earthquake Hazards Program and its partner networks, event uu60471327. Read Mon, Oct 5, 2026, 2:39 AM UTC.