Last Known Eruption
20d 14h 0m ago

Latest Eruptions

Eruption DurationInterval
14 Nov 2024 @ 1201 ie wc19h 16m
13 Nov 2024 @ 1645 wc20d 6h 18m
24 Oct 2024 @ 1127 ns5d 19h 33m
18 Oct 2024 @ 1554 ie wc5h 21m
18 Oct 2024 @ 1033 ie wc4d 18h 31m
13 Oct 2024 @ 1602 ie wc2d 6h 48m
11 Oct 2024 @ 09141d 21h 49m
09 Oct 2024 @ 1125 ie4d 19h 43m
04 Oct 2024 @ 1542 ie wc1d 1h 59m
03 Oct 2024 @ 1343 ie1d 23h 57m
01 Oct 2024 @ 13464m 1d 2h 38m
30 Sep 2024 @ 110811m 17h 11m
29 Sep 2024 @ 1757 ie8h 43m
29 Sep 2024 @ 091421h 17m
28 Sep 2024 @ 1157 ie18h 11m
27 Sep 2024 @ 174617m 3d 9h 12m
24 Sep 2024 @ 083410m 1d 21h 46m
22 Sep 2024 @ 10481d 22h 55m
20 Sep 2024 @ 115313m 19h 35m
19 Sep 2024 @ 161812m 6h 51m
19 Sep 2024 @ 09279m 3d 16h 15m
15 Sep 2024 @ 1712 ns3d 23h 51m
11 Sep 2024 @ 1721 ie wc2d 6h 29m
09 Sep 2024 @ 1052 ns7d 22h 3m
01 Sep 2024 @ 124911.5m 17h 24m
31 Aug 2024 @ 19259m 7h 55m
31 Aug 2024 @ 113010m 22h 14m
30 Aug 2024 @ 13162m 22h 1m
29 Aug 2024 @ 15159m 1d 6h 45m
28 Aug 2024 @ 08309m 15h 47m
27 Aug 2024 @ 164310m 4h 53m
27 Aug 2024 @ 115010m 5h 24m
27 Aug 2024 @ 062611m 22h 46m
26 Aug 2024 @ 074013m 2d 14h 34m
23 Aug 2024 @ 17068.5m 8h 4m
23 Aug 2024 @ 09029m 1d 14h 29m
21 Aug 2024 @ 18332d 5h 51m
19 Aug 2024 @ 1242 ie22h 30m
18 Aug 2024 @ 1412 ie19h 41m
17 Aug 2024 @ 183127m 6d 3h 54m
11 Aug 2024 @ 1437 ns1d 6h 23m
10 Aug 2024 @ 08149m 3d 12h 53m
06 Aug 2024 @ 1921 ie wc10h 8m
06 Aug 2024 @ 091315m 2d 20h 37m
03 Aug 2024 @ 12366h 16m
03 Aug 2024 @ 06209m 16h 12m
02 Aug 2024 @ 140813m 19h 59m
01 Aug 2024 @ 1809 ie3d 2h 57m
29 Jul 2024 @ 1512 ie1d 3h 5m
28 Jul 2024 @ 1207 ns11-12 minutes1d 17m
27 Jul 2024 @ 115026m 2d 11m
25 Jul 2024 @ 1139~3m 2d 22h 38m
22 Jul 2024 @ 13015m 4d 6h 40m
18 Jul 2024 @ 0621 ie19h 37m
17 Jul 2024 @ 104411m 22h 5m
16 Jul 2024 @ 1239 wc16h 10m
15 Jul 2024 @ 202921m 6h 20m
15 Jul 2024 @ 1409 ie3d 21h 43m
11 Jul 2024 @ 16269m 2d 5h 0m
09 Jul 2024 @ 11269m 1d 1h 53m
08 Jul 2024 @ 093317m 2d 13h 10m
05 Jul 2024 @ 20238m 1d 1h 53m
04 Jul 2024 @ 18308m 4d 5h 49m
30 Jun 2024 @ 124113m 5h 56m
30 Jun 2024 @ 064510m 18h 28m
29 Jun 2024 @ 121710m 5h 57m
29 Jun 2024 @ 0620>15m 2d 23h 1m
26 Jun 2024 @ 07197.5m 17h 33m
25 Jun 2024 @ 13469m 1d 3h 2m
24 Jun 2024 @ 104412m 13h 58m
23 Jun 2024 @ 20469m 13h 29m
23 Jun 2024 @ 07179m 18h 7m
22 Jun 2024 @ 13108.5m 2d 1h 55m
20 Jun 2024 @ 1115 wc17h 19m
19 Jun 2024 @ 17566h 44m
19 Jun 2024 @ 1112 ie18h 2m
18 Jun 2024 @ 171014m 1d 10h 45m
17 Jun 2024 @ 0625 ie8h 53m
16 Jun 2024 @ 2132 wc3d 1h 50m
13 Jun 2024 @ 19429h 39m
13 Jun 2024 @ 100318m 4d 16h 45m
08 Jun 2024 @ 1718 ie2d 1h 58m
06 Jun 2024 @ 15206h 12m
06 Jun 2024 @ 09089m 19h 41m
05 Jun 2024 @ 132714m 7h 4m
05 Jun 2024 @ 062314m 12h 27m
04 Jun 2024 @ 1756 ie10d 5h 2m
25 May 2024 @ 1254 wc22h 1m
24 May 2024 @ 145313m 7h 9m
24 May 2024 @ 074414m 2d 21h 2m
21 May 2024 @ 10426m 2d 5h 39m
19 May 2024 @ 0503 wc15h 5m
18 May 2024 @ 135827m 1d 21h 25m
16 May 2024 @ 1633 ie18d 2h 4m
28 Apr 2024 @ 142965d 20h 2m
22 Feb 2024 @ 1727~30m 39d 1h 17m
14 Jan 2024 @ 161048d 3h 34m
27 Nov 2023 @ 12361d 21h 16m
25 Nov 2023 @ 1520 ie wc1d 1h 11m
24 Nov 2023 @ 1409 ie wc39d 21h 20m

Interval Statistics

Interval Count100
Min4h 53m
Max65d 20h 2m
Mean3d 22h 59m
Median1d 1h 56m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
37457 09 Oct 2024 @ 1140 --- mrsteed no longer erupting
36549 25 Aug 2024 @ 1723 25 Aug 2024 @ 1946 BrianR 17:23 First Splash seen after Grotto marathon 17:52 first pressure pool 18:20 second 18:48 third 19:17 fourth, first reasonable boil from fountain 19:46 fifth Left area probably 2 to 3 cycles to go before eruption
36238 03 Aug 2024 @ 0617 --- CraigC splashing, pressure pool full
35673 02 Jul 2024 @ 1015 --- RMichaels Grotto Fountain boiled up at the start of Grotto but did not erupt.
35606 28 Jun 2024 @ 2030 --- BrianR Splashing but no pressure pools yet, leaving area
28813 15 Oct 2023 @ 1158 --- Ben VL Pressure pool up & drop.
27023 12 Jul 2023 @ 1836 --- Ben VL Pressure pool up and dropped. Not sure how many there have been.
26342 15 Jun 2023 @ 1405 --- Graham 1405 Small boil. Pressure Pool low. Also 1434, 1446, break, 1528 high water, good boil, 1546 weak, 1609 strong, almost started, 1643 weak, 1656
25583 20 May 2023 @ 1305 --- Brando boiling ~8 inches
24286 06 Oct 2022 @ 1227 --- DanS In overflow
23474 29 Aug 2022 @ 0959 --- Art Started erupting 3-4’ then stopped after 3 minutes.
21722 04 Jun 2022 @ 1346 --- Graham Pressure Pool up and small boil. Again 1403, 1414, 1427, 1439, 1447 and GF boiling steadily. 1451 rise and boil continues. 1457 GF erupted. 10m of boiling before it committed to an eruption.
21551 28 May 2022 @ 1149 --- Graham Pressure pool up but not full. No boiling in GF. Also 1204, 1211. 1223 up and full. Also 1235, 1250, 1304, 1315, 1326, 1338. 1340 small boil d=3m.
19826 01 Oct 2021 @ 1317 --- SteveO Grotto Fountain bubbling a little bit, 1 st visible in the Pressure Pool.
19770 28 Sep 2021 @ 1513 --- Kitt B Pressure pool is up and dropped at 1515.
19508 12 Sep 2021 @ 1108 --- Graham End 1108
19477 11 Sep 2021 @ 1400 11 Sep 2021 @ 1410 aferrara 1-1.5' boil in lead up to Grotto that did not result in an eruption of GF
19260 03 Sep 2021 @ 1633 --- Brian Tried to start, jetting began to perhaps 4’ max, then died as Grotto started
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
18794 20 Jul 2021 @ 1511 20 Jul 2021 @ 1538 BrianR Grotto Fountain: First heard water boiling: 15:11 No visible water/boiling before Grotto eruption Pressure Pool up: 15:30-15:31
18791 20 Jul 2021 @ 0818 20 Jul 2021 @ 0916 BrianR Grotto Fountain: First heard water boiling 8:18 Visible water/boiling: 9:01 Pressure Pool up: 9:15-9:16
18776 18 Jul 2021 @ 1623 18 Jul 2021 @ 1737 BrianR First heard water boiling: 16:23 Pressure Pool up: 17:29-17:30 17:34-17:37 Visible water/boiling: 17:28-17:30 17:33-17:36 Did not erupt
18775 18 Jul 2021 @ 1230 18 Jul 2021 @ 1321 BrianR First heard water boiling: 12:30 Visible water/boiling 13:16 Did not erupt
18772 18 Jul 2021 @ 0619 18 Jul 2021 @ 0826 BrianR Hear water boiling 6:19 Pressure Pool up: 6:35-6:39 7:28-7:42 8:11-8:26 Visible water/boiling 6:21-7:42 8:14-8:26 Did not erupt
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
18 May 2024 @ 1358 User34 https://www.youtube.com/watch?v=VJsqLYX8V1k Started recording 21 minutes in
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.