| Note ID | Start Time (US/Mountain) | End Time (US/Mountain) | Entrant | Note |
| 37147 |
25 Sep 2024 @ 1133 |
--- |
TSBryan |
nothing further seen as of 1133 |
| 37145 |
25 Sep 2024 @ 1118 |
--- |
TSBryan |
heavy surges |
| 37146 |
25 Sep 2024 @ 1112 |
--- |
TSBryan |
same as at 1106 |
| 37144 |
25 Sep 2024 @ 1106 |
--- |
TSBryan |
attempted eruption, doming and rolling the pool but no splash. |
| 17197 |
26 May 2021 @ 1800 |
26 May 2021 @ 1858 |
JSJ |
In very light roiling and/or light bubbling at 1800. Small, brief doming at 1858. |
| 13099 |
07 Aug 2019 @ 1900 |
07 Aug 2019 @ 1926 |
JSJ |
No activity at all from Middle Sister, but I've seen pauses much longer than this recently. No other activity in the entire Three Sister complex, except Three Crater eruptions. |
| 13083 |
06 Aug 2019 @ 1505 |
06 Aug 2019 @ 1808 |
JSJ |
All closed intervals. Occasional blipping or roiling in lieu of an eruption. All eruptions were single brief bursts, with one double burst. One or two were ~2-3 seconds in duration. |
| 13054 |
05 Aug 2019 @ 1203 |
05 Aug 2019 @ 1341 |
JSJ |
All closed intervals. Some roiling and blipping events. All eruptions were single short bursts of varying sizes. |
| 13027 |
04 Aug 2019 @ 1027 |
04 Aug 2019 @ 1625 |
JSJ |
All closed intervals. Under constant observation during this time. |
| 12384 |
06 Jul 2019 @ 1305 |
--- |
DanS |
Domed water. Did not erupt. |
| 9091 |
09 Jul 2018 @ 1145 |
09 Jul 2018 @ 1218 |
Micah Kipple |
Occasional bubbling vent just on the south edge of the crater towards south sister. |
| 5288 |
23 Aug 2017 @ 1117 |
23 Aug 2017 @ 1155 |
Tara |
Under observation during this time, no eruptions. |
| 14373 |
31 Aug 1995 @ 0000 |
31 Aug 1995 @ 2359 |
JarnoO |
active |