Last Known Eruption
22h 56m ago

Latest Eruptions

Eruption DurationInterval
25 Jul 2021 @ 15211d 3h 28m
24 Jul 2021 @ 11539m 15h 29m
23 Jul 2021 @ 202414m 8h 41m
23 Jul 2021 @ 114319m 17h 52m
22 Jul 2021 @ 175123m 7h 58m
22 Jul 2021 @ 095325m 4d 17h 57m
17 Jul 2021 @ 15566m 19h 35m
16 Jul 2021 @ 2021 ie wc9h 45m
16 Jul 2021 @ 10362418h 53m
15 Jul 2021 @ 15438h 0m
15 Jul 2021 @ 0742:558m 25s 14h 43m
14 Jul 2021 @ 165925m 7h 41m
14 Jul 2021 @ 0918 ns28m 2d 20h 49m
11 Jul 2021 @ 1229~5m 21h 19m
10 Jul 2021 @ 15109.5m 8h 28m
10 Jul 2021 @ 0642 ns~20m 16h 5m
09 Jul 2021 @ 143719m 5h 27m
09 Jul 2021 @ 091022m 7d 13h 35m
01 Jul 2021 @ 19358m 42s 4d 3h 33m
27 Jun 2021 @ 16021d 5h 37m
26 Jun 2021 @ 1025 ie2d 13h 47m
23 Jun 2021 @ 2038 ie2d 5h 5m
21 Jun 2021 @ 153313m 36s 1d 6h 3m
20 Jun 2021 @ 093016m 8d 22h 11m
11 Jun 2021 @ 11191d 21h 9m
09 Jun 2021 @ 14102m 19h 34m
08 Jun 2021 @ 1836 ie wc>19m 1d 3h 59m
07 Jun 2021 @ 143722m 4d 1h 19m
03 Jun 2021 @ 131827m 1d 1h 14m
02 Jun 2021 @ 1204 ie2d 23h 40m
30 May 2021 @ 1224 ie13d 2h 6m
17 May 2021 @ 101818m 20s 17h 19m
16 May 2021 @ 165916m 18d 7h 27m
28 Apr 2021 @ 093218h 58m
27 Apr 2021 @ 1434 ns1d 1h 51m
26 Apr 2021 @ 124319m 1d 23h 22m
24 Apr 2021 @ 132125m 43s 16h 51m
23 Apr 2021 @ 203027m 38s 9h 23m
23 Apr 2021 @ 1107 ie>23m 1d 16h 46m
21 Apr 2021 @ 1821 ie wc1d 9h 7m
20 Apr 2021 @ 091421m 15s 61d 22h 52m
17 Feb 2021 @ 0922 ie23d 18h 23m
24 Jan 2021 @ 1459 ie31d 5h 14m
24 Dec 2020 @ 0945 ie66d 20h 36m
18 Oct 2020 @ 1409~30m 5d 19h 59m
12 Oct 2020 @ 1810~29m 4d 9h 41m
08 Oct 2020 @ 08299m 28s 1d 19h 57m
06 Oct 2020 @ 1232 ie wc3d 31m
03 Oct 2020 @ 1201 ie wc20h 9m
02 Oct 2020 @ 1552 ie4d 1h 6m
28 Sep 2020 @ 144623h 20m
27 Sep 2020 @ 1526~10m 21h 31m
26 Sep 2020 @ 1755 ie5d 3h 34m
21 Sep 2020 @ 14211m 5h 54m
21 Sep 2020 @ 082712m 24s 6d 12h 39m
14 Sep 2020 @ 19482m 14d 7h 44m
31 Aug 2020 @ 120427m 23h 29m
30 Aug 2020 @ 12351d 20h 31m
28 Aug 2020 @ 160424m 3d 58m
25 Aug 2020 @ 15062.5m 22h 7m
24 Aug 2020 @ 16598m 7h 10m
24 Aug 2020 @ 09494.5m 2d 19h 7m
21 Aug 2020 @ 14421d 6h 14m
20 Aug 2020 @ 082817m 32s 1d 17h 48m
18 Aug 2020 @ 144026m 13s 2d 2h 58m
16 Aug 2020 @ 114220h 19m
15 Aug 2020 @ 15231d 3h 19m
14 Aug 2020 @ 1204 ie wc1d 3h 19m
13 Aug 2020 @ 0844:5521m 28s 1d 1h 35m
12 Aug 2020 @ 0709 ie5d 22h 33m
06 Aug 2020 @ 0836 ns>12m 1d 19h 12m
04 Aug 2020 @ 1323:56 ie13h 47m
03 Aug 2020 @ 2336 ie wc8d 5h 46m
26 Jul 2020 @ 1750 ie wc8d 7h 4m
18 Jul 2020 @ 1046 ie wc3d 18h 23m
14 Jul 2020 @ 162311m 23s 12d 22h 23m
01 Jul 2020 @ 18002m 22h 45m
30 Jun 2020 @ 191513m 7h 11m
30 Jun 2020 @ 120412m 22h 48m
29 Jun 2020 @ 131629m 2d 14h 50m
26 Jun 2020 @ 2226 ie8h 46m
26 Jun 2020 @ 134022m 6d 31m
20 Jun 2020 @ 1309 ie1d 3h 43m
19 Jun 2020 @ 0926 ie7d 41m
12 Jun 2020 @ 0845 ie wc2d 16h 52m
09 Jun 2020 @ 1553 ie3d 7h 53m
06 Jun 2020 @ 0800 A2d 13h 37m
03 Jun 2020 @ 18232d 2h 24m
01 Jun 2020 @ 1559 ie12d 4h 42m
20 May 2020 @ 1117 ie wc2d 21h 27m
17 May 2020 @ 1350 ie wc4d 2h 37m
13 May 2020 @ 1113 ie wc2d 18h 16m
10 May 2020 @ 1657 ie1d 2h 28m
09 May 2020 @ 1429 ie wc17d 20h 50m
21 Apr 2020 @ 173912d 4h 13m
09 Apr 2020 @ 1326 ie wc18d 20h 38m
21 Mar 2020 @ 1648 ie wc11d 5h 11m
10 Mar 2020 @ 1137 ? ns wc8d 1h 28m
02 Mar 2020 @ 0909 ?1d 10h 8m
29 Feb 2020 @ 2301 E114d 8h 24m

Interval Statistics

Interval Count100
Min5h 27m
Max114d 8h 24m
Mean6d 6h 14m
Median1d 20h 14m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
18571 22 Jul 2021 @ 0950 --- SteveO 5th Pressure Pool up with boiling in Grotto Fountian.
18570 22 Jul 2021 @ 0913 22 Jul 2021 @ 0917 SteveO 4th Pressure Pool up with boiling 3 to 4 feet in Grotto Fountian. Pressure Pool dropped 0917.
18569 22 Jul 2021 @ 0833 22 Jul 2021 @ 0836 SteveO 3rd Pressure Pool up with boiling in Grotto Fountain. Pressure Pool dropped at 0836
18568 22 Jul 2021 @ 0803 22 Jul 2021 @ 0805 SteveO 2nd Pressure Pool up with Grotto Fountian boil. Pressure Pool dropping at 0805.
18593 22 Jul 2021 @ 0728 22 Jul 2021 @ 0729 BrianR First Pressure Poor up with fountain boil
18592 22 Jul 2021 @ 0701 --- BrianR First appearance of water after Grotto marathon
18069 24 Jun 2021 @ 0850 24 Jun 2021 @ 0856 CrisG pressure pool up. low splashing from cone. pool dropped by 0905.
17770 14 Jun 2021 @ 1235 --- CraigC pressure pool up, Grotto Ftn built up to about 5 foot bursting that collapsed after Grotto started
17769 14 Jun 2021 @ 1225 --- CraigC pressure pool up, light spitting in GF
17747 13 Jun 2021 @ 1352 --- CraigC pressure pool up
17746 13 Jun 2021 @ 1317 --- CraigC pressure pool up
17745 13 Jun 2021 @ 1220 --- CraigC pressure pool up
17716 12 Jun 2021 @ 1654 --- CraigC pressure pool up
17705 12 Jun 2021 @ 1313 --- CraigC pressure pool up
17704 12 Jun 2021 @ 1258 --- CraigC pool has not dropped, completely full now
17703 12 Jun 2021 @ 1120 --- CraigC pressure pool up
17700 12 Jun 2021 @ 1048 --- CraigC water spitting up a few inches, 1053 water visible in pressure pool about 4 inches below top
17695 12 Jun 2021 @ 1000 --- CraigC pressure pool up
17669 11 Jun 2021 @ 1117 --- CraigC pressure pool up
17668 11 Jun 2021 @ 1106 --- CraigC pressure pool up, right back down, low energy
17666 11 Jun 2021 @ 1033 --- CraigC pressure pool up, strong boil from Grotto Fountain
17664 11 Jun 2021 @ 0952 --- CraigC pressure pool up, strong 2 foot boil in Grotto Fountain
17662 11 Jun 2021 @ 0910 --- CraigC pressure pool up
17658 11 Jun 2021 @ 0830 --- CraigC pressure pool up
17656 11 Jun 2021 @ 0752 --- CraigC pressure pool up
17611 09 Jun 2021 @ 1401 --- CraigC pressure pool up
17610 09 Jun 2021 @ 1320 --- CraigC pressure pool up
17609 09 Jun 2021 @ 1309 --- CraigC pressure pool up
17608 09 Jun 2021 @ 1254 --- CraigC pressure pool up
17607 09 Jun 2021 @ 1247 --- CraigC pressure pool up
17606 09 Jun 2021 @ 1157 --- CraigC pressure pool up
17605 09 Jun 2021 @ 1122 --- CraigC pressure pool up
17597 09 Jun 2021 @ 0708 --- CraigC water up in pressure pool, bubbling in Grotto Fountain
17595 09 Jun 2021 @ 0646 --- CraigC brief spitting
17560 07 Jun 2021 @ 1435 --- CraigC pressure pool up
17559 07 Jun 2021 @ 1350 --- CraigC pressure pool up
17558 07 Jun 2021 @ 1304 --- CraigC pressure pool up
17475 05 Jun 2021 @ 1226 --- CraigC pressure pool up
17431 04 Jun 2021 @ 1218 --- CraigC pressure pool up
17430 04 Jun 2021 @ 1203 --- CraigC pressure pool up, splashing in Grotto Geyser
16937 28 Apr 2021 @ 0915 --- CraigC Pressure pool up, small bubbling from GF
16934 27 Apr 2021 @ 1401 --- CraigC Pressure pool up, dropped after entry, then back up at 1405, GF began small bubbling.
16926 26 Apr 2021 @ 1155 --- CraigC Pressure pool up, GF spouting for 5 mins then dropped
16925 26 Apr 2021 @ 1116 --- CraigC pressure pool full, GF spouting 3 to 4 feet variable for 5 mins before collapsing
16086 12 Sep 2020 @ 1352 --- CraigC pressure pool up
16085 12 Sep 2020 @ 1305 --- CraigC pressure pool up
16065 11 Sep 2020 @ 1534 --- CraigC pressure pool is full
15951 04 Sep 2020 @ 1003 --- TheHikingDude pool empty
15929 02 Sep 2020 @ 0811 --- CraigC pressure pool up, small bubbling in GF
15912 31 Aug 2020 @ 1201 --- CraigC pressure pool rising. 1202 bursting in GF
15910 31 Aug 2020 @ 1122 --- CraigC pressure pool up, then fell, small bursting from GF
15909 31 Aug 2020 @ 1040 --- CraigC pressure pool up, just dropped. small bubbling from gf
15719 23 Aug 2020 @ 1247 23 Aug 2020 @ 1413 BrianR Overflowed water at various times in buildup to Grotto eruption, but never boiled. Pressure Pool had visible water ~ 95% of this time frame. This and South Grotto Fountain series of eruptions was due to Spa having a flowing runoff channel to the river and all three of its vents bubbling (I.e., it was trying to start at the same time as Grotto). Also Grotto Central Vents were active in this time frame when South Grotto Fountain was not erupting. Demetri will provide notes on Startling during this time frame
13539 04 Sep 2019 @ 1224 --- c.barwin end time
12835 28 Jul 2019 @ 0938 --- rbwhitaker Got over two feet tall then backed down to nothing
12033 29 Jun 2019 @ 1454 --- Polly Wet around Grotto Fountain.
11992 27 Jun 2019 @ 1712 27 Jun 2019 @ 2007 BrianR After aborted eruption, the Grotto system went into a stalled pattern. Grotto Fountain was in a continuous boil up to 2 ft ( mostly 1 ft and under) from 17:49 to 19:28, 19:34 to 1943, and 19:51 to 19:58. The “pressure pool” was rising and falling just barely in and out of view from 17:20 to 18:51, then staying always in view until Grotto Fountain finally erupted at 20:09. Grotto was silent except for three one minute grumbles during this time. All Spa vents were off and the pool rose only 3 inches during this time.
11991 27 Jun 2019 @ 1708 27 Jun 2019 @ 1711 BrianR 6 to 10 ft eruption aborted, no Grotto
11336 23 May 2019 @ 1420 23 May 2019 @ 1521 Kyle as pressure pool rose and dropped Grotto Fountain bubbled/boiled to a height just above the height of it's cone for brief periods when the pressure pool was full and would stop when pressure pool level dropped
11264 18 May 2019 @ 1348 --- Mkeller Repeat of what happened at 12:56
11265 18 May 2019 @ 1256 --- Mkeller Erupted to 3-4 feet for about 3 minutes. Grotto tried to start. Central Vents erupted instead.
8982 25 Jun 2018 @ 1559 --- BrianR “Pressure Pool” up at 15:59 through 16:06, 263 minutes after last Grotto. Grotto Fountain water to 3 ft at 16:01, no eruption prior to Grotto
8981 25 Jun 2018 @ 1527 --- BrianR “Pressure Pool” up at 15:27 through 15:31 no Grotto Fountain water. 231 minutes after last Grotto
8980 24 Jun 2018 @ 1523 --- BrianR “Pressure Pool” up 15:23 through 15:26, no Grotto Fountain water. 262 minutes after last Grotto
7047 23 Sep 2017 @ 1600 23 Sep 2017 @ 1606 Polly Bubbles increasing to ~6 inches steady, then off 1606.
3517 20 Aug 2016 @ 1931 --- Kitt B Grotto Fountain ended at 1931
2533 11 Oct 2015 @ 1223 --- Siegmund Bubbling vigorously 1223; boiling hard 1228-1231, but never got more than ~30cm high
2151 14 Aug 2015 @ 1312 --- JSJ Blipping at 1312 (Grotto & Rocket started at 1314).
1656 28 May 2015 @ 1448 --- mhreed Saw two distinct steam clouds from F&M. By the time I walked up to the Grotto area, Grotto Fountain was at 10 ft. and dying down. Not sure if missed or aborted eruption.
1612 19 May 2015 @ 1347 19 May 2015 @ 1358 JSJ Intermittent small blipping to very low spouting from 1347 to 1358. No more after Grotto Geyser eruption start at 1358.
1005 29 Aug 2008 @ 0000 29 Aug 2008 @ 2359 BoekelUpload
1352 09 Jun 2007 @ 0900 09 Jun 2007 @ 0909 BoekelUpload 9:0x
3879 03 Jul 2006 @ 0700 03 Jul 2006 @ 1545 Tara Grotto Fountain had been having periodic boiling episodes since sometime before 0700. These episodes alternated with eruptions by South Grotto Fountain. There were three stronger episodes at 0711, 1100, and 1400. These occurred midway between hourly Giant hot periods. When Grotto Fountain finally did erupt, it was weak and lasted only 5 minutes, but Grotto did follow at 1548.
15329 19 Nov 1996 @ 1103 --- JarnoO overflowing heavily ~15-20 gpm
EntrySourceLinkComment
26 Jun 2020 @ 1345 JarnoO https://www.youtube.com/watch?v=u5PSt5bVzBI As seen from the webcam, by LindaG.
04 Jun 2019 @ 1600 Janet Jones https://www.instagram.com/p/ByTruIXgn3S/?igshid=1p95trg6cm06a video - just wow!
06 Jun 2016 @ 1728 JSJ https://www.youtube.com/watch?v=zx8TS3vUBX8#t=5m32s Video compilation (starting at time stamp 5:32) of Grotto Fountain Geyser's 5:28 to 5:50 PM eruption on 6 June 2016.
12 May 2013 @ 1246 JSJ https://www.youtube.com/watch?v=Oezz90AHebA Video by Will Boekel of Grotto Fountain Geyser in eruption at 12:46 PM-onward on 12 May 2013.
27 Jun 2013 @ 1323 JSJ https://www.youtube.com/watch?v=gefNjjZY-vo Video by Will Boekel showing Grotto Fountain Geyser's 1:23 PM-onward eruption on 27 June 2013.
06 Jun 2016 @ 1728 JSJ https://www.flickr.com/photos/jsjgeology/30841241351 Photo (1 of 23) of Grotto Fountain Geyser's 5:28 to 5:50 PM eruption on 6 June 2016.
12 Jul 2013 @ 0835 JSJ https://www.youtube.com/watch?v=n2NnnyK4nYo Video by Micah Kipple of the Grotto Fountain Geyser-South Grotto Fountain Geyser dual eruption during the morning of 12 July 2013.
BaselineDistance (ft)Description
West Side 100Note this one is off trail beyond the bumper logs on a cinder block just beyond the sign on the log to the west side.