| Note ID | Start Time (US/Mountain) | End Time (US/Mountain) | Entrant | Note |
| 34897 |
04 Jun 2024 @ 1554 |
04 Jun 2024 @ 1728 |
JSJ |
No Three Crater eruptions while Little Brother was active, with one exception (1701 to 1702). Obscuring steam much of the time, but no other Three Crater eruptions seen or heard. |
| 34845 |
02 Jun 2024 @ 1532 |
02 Jun 2024 @ 1642 |
JSJ |
All closed intervals: 25m, 22m, 23m. |
| 27424 |
05 Aug 2023 @ 1752 |
05 Aug 2023 @ 1911 |
JSJ |
Closed intervals: 20m, 20m, 15m, 17m. True intervals (= eruption end to next eruption start): 11m, 11m, 9m, 10m. Durations: ~9m, ~9m, ~6m, ~7m, ~7m. |
| 25222 |
23 Apr 2023 @ 1409 |
23 Apr 2023 @ 1513 |
DanS |
No eruption this timeframe |
| 20742 |
21 Jan 2022 @ 1438 |
--- |
aferrara |
Churning and thumping |
| 17641 |
10 Jun 2021 @ 1600 |
10 Jun 2021 @ 1630 |
Graham |
No eruptions of Three Crater or Middle Sister seen during this time. |
| 17194 |
26 May 2021 @ 1800 |
26 May 2021 @ 1902 |
JSJ |
All closed intervals. Fairly regular erupter. Most durations are a bit over a minute. Waves from splashing result in slight overflow of North Sister Spring's basin. |
| 16112 |
13 Sep 2020 @ 1642 |
--- |
Art |
Pool calm |
| 13806 |
26 Sep 2019 @ 1548 |
26 Sep 2019 @ 1646 |
DanS |
No eruptions. Domed water at 1616. Windy. |
| 13028 |
04 Aug 2019 @ 1029 |
04 Aug 2019 @ 1626 |
JSJ |
All closed intervals. Have never before seen this geyser be so regular in intervals and durations. All were ~1 to 2 minutes long. Usual spaced splashing. |
| 12367 |
30 Dec 1993 @ 0000 |
30 Dec 1993 @ 2359 |
JarnoO |
I's 7-9m; d 1-3m; height 3' |