Last Known Eruption
2d 14h 47m ago

Latest Eruptions

Eruption DurationInterval
18 May 2019 @ 14472d 19h 51m
15 May 2019 @ 1856 ie wc1d 5h 37m
14 May 2019 @ 131910h 56m
14 May 2019 @ 0223 ? wc10h 22m
13 May 2019 @ 1601 ie wc1d 6h 26m
12 May 2019 @ 0935 ie wc13h 33m
11 May 2019 @ 2002 ie1d 23h 43m
09 May 2019 @ 2019 ie wc10h 17m
09 May 2019 @ 1002 ns19h 54m
08 May 2019 @ 1408 ie2d 3h 24m
06 May 2019 @ 1044 ie21h 31m
05 May 2019 @ 1313 ie wc6h 41m
05 May 2019 @ 0632 ? ie wc21h 0m
04 May 2019 @ 0932 ie22h 0m
03 May 2019 @ 113216h 5m
02 May 2019 @ 1927 ie7h 13m
02 May 2019 @ 1214 ie18h 10m
01 May 2019 @ 1804 ie1d 2h 44m
30 Apr 2019 @ 1520 ie2h 14m
30 Apr 2019 @ 1306 ie1d 2h 47m
29 Apr 2019 @ 1019 ie1h 0m
29 Apr 2019 @ 0919 ie1d 19h 30m
27 Apr 2019 @ 134917h 9m
26 Apr 2019 @ 2040 ie1d 2h 4m
25 Apr 2019 @ 18361d 2h 36m
24 Apr 2019 @ 1600 ie wc3d 20h 18m
20 Apr 2019 @ 19429h 20m
20 Apr 2019 @ 102220h 12m
19 Apr 2019 @ 1410 ns23h 21m
18 Apr 2019 @ 1449 wc4h 55m
18 Apr 2019 @ 09542d 19h 28m
15 Apr 2019 @ 1426 ie wc1d 23m
14 Apr 2019 @ 1403 ie wc1d 3h 52m
13 Apr 2019 @ 1011 ns wc24d 17h 4m
19 Mar 2019 @ 17076h 10m
19 Mar 2019 @ 10571h 40m 4d 1h 37m
15 Mar 2019 @ 0920 ie11d 17h 26m
03 Mar 2019 @ 1454 ie35d 6h 53m
27 Jan 2019 @ 0801 ie19h 40m
26 Jan 2019 @ 1221 ie1d 1h 29m
25 Jan 2019 @ 1052 ie1d 23h 27m
23 Jan 2019 @ 1125>1d 22h 23m
21 Jan 2019 @ 13021d 3h 32m
20 Jan 2019 @ 0930 ie16d 21h 5m
03 Jan 2019 @ 1225 ie7d 23h 25m
26 Dec 2018 @ 1300 ie wc1d 1h 47m
25 Dec 2018 @ 1113 ie51d 3h 17m
04 Nov 2018 @ 0756 ie26m
04 Nov 2018 @ 0730 ie14h 10m
03 Nov 2018 @ 1820 ie3h 10m
03 Nov 2018 @ 1510 ie wc4h 40m
03 Nov 2018 @ 1030 ie23h 26m
02 Nov 2018 @ 1104 ie21h 30m
01 Nov 2018 @ 1334 ie2d 21h 32m
29 Oct 2018 @ 1602 ie wc1d 6h 58m
28 Oct 2018 @ 0904 ie wc19h 24m
27 Oct 2018 @ 1340 ie wc5h 49m
27 Oct 2018 @ 0751 ie wc5d 21h 44m
21 Oct 2018 @ 1007 ie1d 20h 46m
19 Oct 2018 @ 132157m 2d 18h 15m
16 Oct 2018 @ 19067h 51m
16 Oct 2018 @ 1115 ns1d 2h 49m
15 Oct 2018 @ 0826 ie23h 38m
14 Oct 2018 @ 0848 ie wc19h 51m
13 Oct 2018 @ 1257 ie18h 46m
12 Oct 2018 @ 1811 ie wc1h 53m
12 Oct 2018 @ 1618 ns1d 2h 43m
11 Oct 2018 @ 1334:34 ie2h 24m
11 Oct 2018 @ 1110 ie19h 33m
10 Oct 2018 @ 1536:50 ns3h 37m
10 Oct 2018 @ 115922h 5m
09 Oct 2018 @ 1353:015h 25m 3s
09 Oct 2018 @ 0827:58 ns19h 35m
08 Oct 2018 @ 1252 ie3h 50m
08 Oct 2018 @ 0902 ns15h 53m
07 Oct 2018 @ 1709 ie5h 4m
07 Oct 2018 @ 1205 ie4h 6m
07 Oct 2018 @ 0759 ie wc15h 49m
06 Oct 2018 @ 16101h 45m
06 Oct 2018 @ 1425 ns wc20h 50m
05 Oct 2018 @ 1735 ie3h 45m
05 Oct 2018 @ 1350~44m 3h 43m
05 Oct 2018 @ 100721h 50m
04 Oct 2018 @ 12175h 38m
04 Oct 2018 @ 0639 ie11h 16m
03 Oct 2018 @ 19235h 26m
03 Oct 2018 @ 13574h 57m
03 Oct 2018 @ 0900 ie3h 35m
03 Oct 2018 @ 0525 ie9h 4m
02 Oct 2018 @ 202141m 7h 25m
02 Oct 2018 @ 1256 ie1h 46m
02 Oct 2018 @ 1110 ie2h 43m
02 Oct 2018 @ 0827 ns19h 38m
01 Oct 2018 @ 124959m 3h 59m
01 Oct 2018 @ 0850 A17h 10m
30 Sep 2018 @ 15404h 3m
30 Sep 2018 @ 1137 ns3h 50m
30 Sep 2018 @ 0747 ie12h 51m
29 Sep 2018 @ 1856 ie4h 24m
29 Sep 2018 @ 1432 ie6h 59m

Interval Statistics

Interval Count100
Min26m
Max51d 3h 17m
Mean2d 7h 30m
Median19h 28m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
11219 12 May 2019 @ 1630 --- Micah Kipple Still in Marathon at 1630.
11200 10 May 2019 @ 1030 --- udo Grotto off. Was on when I arrived about 0800. Possibly a 10k. Marathon pool down several inches. Bijou weak but not off.
11189 08 May 2019 @ 1242 --- MikeG Eruption started at 12:42.
11177 06 May 2019 @ 0656 --- RLJones Grotto is off and pressure pool is empty
11171 05 May 2019 @ 0733 05 May 2019 @ 0850 RLJones In eruption at 0733, off at approx 0850
11135 29 Apr 2019 @ 1855 --- Polly Grotto still ie from this morning. Snowstorm is coming in and I’m losing visibility.
11128 28 Apr 2019 @ 1108 28 Apr 2019 @ 1935 Polly Grotto group has been pretty quiet today (as observed from the Inn parking lot). The temperature today was below freezing all day, so steam clouds around the basin have been easy to see. Starting at about 1800, I could see varying small steam clouds in various spots in the area. There was one large steam cloud at 1758 that may have been Oblong. Duration was ~7 minutes with a slowdown at about 5 minutes.
11076 25 Apr 2019 @ 1739 --- Graham No Grotto steam cloud seen on webcam. Looks like just a big attempt at erupting by Grotto Fountain per DanS report.
11032 20 Apr 2019 @ 0949 20 Apr 2019 @ 1022 RMichaels Prior to Grotto's eruption, water was rising and falling cyclically in the pressure pool. I don't recall seeing it do this at all last year. No activity seen in Grotto Fountain during this period or at any other time today.
10980 13 Apr 2019 @ 1000 13 Apr 2019 @ 1930 MikeG In eruption from 10:09 until at least 19:20.
10873 20 Jan 2019 @ 1434 --- Graham still ie. variable spring down 6" and boiling. in a marathon. still ie 1615.
10792 25 Dec 2018 @ 1611 --- Janet White Trying to start - couldn’t wait due to early dinner reservations.
10705 02 Nov 2018 @ 1322 --- WillBoekel turned off at this time
10644 21 Oct 2018 @ 1042 --- rbwhitaker Off by 1042
10596 09 Oct 2018 @ 0726 --- hkoenig Off, but noisy.
10547 04 Oct 2018 @ 0815 04 Oct 2018 @ 0845 William Grotto still ie during the time I observed.
10534 02 Oct 2018 @ 2322 --- Tara No eruption yet.
10489 28 Sep 2018 @ 1028 --- Tara Catchbasins steamy, runoff channels had light flow amd Variable down ~1/2 inch. Possible missed eruption?
10463 26 Sep 2018 @ 1007 --- Micah Kipple Off. No rocket.
10351 23 Sep 2018 @ 0025 --- Tara Had not started again as of 0025.
10207 15 Sep 2018 @ 0908 --- Brian Grotto off
10184 13 Sep 2018 @ 1824 --- Brian Ended at 1824
10176 13 Sep 2018 @ 0940 --- Polly Grotto off.
10147 11 Sep 2018 @ 1216 --- Kyle eruption ended
10101 08 Sep 2018 @ 1218 --- rbwhitaker Off at 1218
10069 06 Sep 2018 @ 1500 --- Kyle Grotto end at 1500 D=1hr 39m
10000 03 Sep 2018 @ 0955 --- Pat Snyder Off at 0955
9972 01 Sep 2018 @ 0432 --- Kyle ended at 04:32
9783 19 Aug 2018 @ 1615 --- Micah Kipple Off....
9752 17 Aug 2018 @ 1804 --- Tara Central Vents i.e.
9747 17 Aug 2018 @ 1356 --- Tara Grotto had several splashes inside its cone and Central Vents started, still i.e. at 1406.
9675 12 Aug 2018 @ 1643 12 Aug 2018 @ 1648 minissa Came upon Grotto, Rocket, and Central Vents splashing as though ie but all had shut down by 1447. Honestly not sure at this time if this was the end of a short, early eruption or an attempted start with something like a Central Vent delay???
9670 12 Aug 2018 @ 1420 --- BobInSLC 10:19 eruption still going strong
9671 12 Aug 2018 @ 1417 --- minissa Grotto turned back on after Rocket major approx 1417, then had turned off by end of Grand approx 1455
9601 10 Aug 2018 @ 1532 --- Tara Ended at about this time, definitely off by 1535. There may have been a Rocket major at 1510 but I could not see for sure from Fan & Mortar.
9578 09 Aug 2018 @ 1321 --- Tara Grotto end, no Rocket.
9571 09 Aug 2018 @ 0821 --- Tara Grotto off by this time.
9549 08 Aug 2018 @ 1338 --- Tara Grotto end.
9525 07 Aug 2018 @ 2025 --- Brian Grotto end
9455 03 Aug 2018 @ 2044 --- Tara Grotto off.
9431 03 Aug 2018 @ 1321 --- donnielg Grotto off
9428 03 Aug 2018 @ 0950 --- donnielg Off at 9:50
9424 03 Aug 2018 @ 0647 --- Brian Grotto off
9372 01 Aug 2018 @ 1655 --- rbwhitaker Grotto off
9265 21 Jul 2018 @ 1657 --- deanl grotto ended
9205 15 Jul 2018 @ 1913 --- Micah Kipple Grotto is off.
9201 15 Jul 2018 @ 1715 --- hkoenig Grotto ends. D=2h55m
9198 15 Jul 2018 @ 1154 --- deanl ended with last splashes
9183 14 Jul 2018 @ 1434 --- deanl ended - Rocket killed it I guess
9168 13 Jul 2018 @ 0627 --- JimS Ended about 0625.
9144 11 Jul 2018 @ 2024 --- bhoppe Grotto off
9113 10 Jul 2018 @ 1252 --- bhoppe off at 1252
9006 04 Jul 2018 @ 0910 --- Kyle Grotto Off
9017 03 Jul 2018 @ 1320 --- Tom C. Grotto off.
8897 26 Jun 2018 @ 0611 --- BrianR Turned off
8828 21 Jun 2018 @ 0620 --- JimS Quiet now but Marathon Pool down about 6 inches
8791 19 Jun 2018 @ 1655 --- User34 Shutting off
8728 16 Jun 2018 @ 1735 --- CrisG off after rocket
8719 16 Jun 2018 @ 1250 --- Polly Grotto off by 1250 (after Rocket).
8870 16 Jun 2018 @ 1135 --- Polly Central Vents ie
8695 15 Jun 2018 @ 1507 --- Mkeller End 1502
8692 15 Jun 2018 @ 1044 --- CrisG off. steaming gently
8682 14 Jun 2018 @ 2018 --- Tara Grotto off.
8677 14 Jun 2018 @ 1230 --- Polly Grotto off after Rocket.
8657 13 Jun 2018 @ 1255 --- CrisG eruption has ended. Quietly steaming
8521 07 Jun 2018 @ 1428 --- underarockphoto Off following rocket
8481 06 Jun 2018 @ 1502 --- Polly Grotto off 1502 (after Rocket).
8476 06 Jun 2018 @ 0628 --- JimS Off by 0628 after Rocket.
8464 05 Jun 2018 @ 1600 --- Polly Grotto off shortly after Rocket.
8452 05 Jun 2018 @ 0845 --- JimS Ended about 0845
8451 04 Jun 2018 @ 0815 --- Kitt B Grotto was not in eruption during Giant Hot Period
8375 31 May 2018 @ 1646 --- geysergaze Grotto off
8358 30 May 2018 @ 2023 --- Graham Grotto turned off. Believe this is the end of the 1500 eruption. Spa was full at 1800 but I didn't see it erupting. Bijou was weaker than normal at 1900. Then there was a good hot period at 1956.
8342 29 May 2018 @ 1654 --- Art Grotto off
8340 29 May 2018 @ 1155 --- EricZ grotto off
8226 17 May 2018 @ 2004 --- Tara Grotto off.
8221 17 May 2018 @ 1310 --- BobInSLC Grotto off
8208 15 May 2018 @ 1807 --- Polly Grotto appears to be off (from Castle).
8215 15 May 2018 @ 1524 --- Tom C. FWIW, Grotto had three false starts (rocket splashing to ~6', water 4'-10' above Grotto, and just enough water out the back to make an experienced observer get a radio out and check the time - one was erroneously called) between the 1146 end and 1608 start. One at 1316, one circa 1440, and one at 1514. I also saw one sometime prior to the 1324 eruption on the 14th.
8202 15 May 2018 @ 1146 --- bbev off at 1146
8151 10 May 2018 @ 1945 --- Bijoumonkey Grotto off ~1945 per Tara
8123 08 May 2018 @ 1820 --- Bijoumonkey Grotto end ~1820
8079 05 May 2018 @ 1404 --- sfavor off/calm at the moment
8052 02 May 2018 @ 0915 --- WillBoekel recently turned off. little bit of water trickling down runoff channel
8050 01 May 2018 @ 1026 --- Micah Kipple Rocket did not shut grotto down. Still in marathon.
8029 28 Apr 2018 @ 0755 --- Micah Kipple Grotto off
7993 23 Apr 2018 @ 0652 --- RMichaels Quiet, water down a few inches in marathon pool.
7984 21 Apr 2018 @ 1347 --- DanS Still erupting 1250 Off 1330.
7746 24 Oct 2017 @ 1643 --- DanS Still off 1643
7538 29 Sep 2017 @ 1153 --- Polly Off before 1153. Strong and lengthy Rocket at start.
7535 29 Sep 2017 @ 0905 --- Kitt B not erupting
7046 23 Sep 2017 @ 1512 23 Sep 2017 @ 1520 Polly Central Vents delay.
7045 23 Sep 2017 @ 1404 23 Sep 2017 @ 1420 Polly Central Vents delay. (Grotto made a strong attempt but did not start.)
6852 19 Sep 2017 @ 1138 19 Sep 2017 @ 1246 Polly At 1238, Grotto appeared to be ie from the Inn parking lot. At 1228ie I saw heavy steam while watching Grand. Grotto was already off when I approached - noises like it just shut down and steam in the runoff channel
6285 11 Sep 2017 @ 1610 --- Kitt B Grotto ended at 1747.
5958 08 Sep 2017 @ 1445 --- B**2 Rocket tried, but both shut down.
5905 08 Sep 2017 @ 0930 --- c.barwin Off, some steam.
5566 01 Sep 2017 @ 1620 --- LotusBaker no rocket grotto off
5562 31 Aug 2017 @ 2055 --- Tara No Grotto yet.
5549 31 Aug 2017 @ 1708 --- LotusBaker grotto off
EntrySourceLinkComment
15 Aug 2018 @ 0941 JSJ https://www.flickr.com/photos/jsjgeology/32563168958 Photo of initial runoff (approaching Variable Spring) from Grotto Geyser's 9:41 AM-onward eruption on 15 August 2018.
15 Aug 2018 @ 0941 JSJ https://www.flickr.com/photos/jsjgeology/44618689690 Photo of Grotto Geyser's 9:41 AM-onward eruption on 15 August 2018.
14 Aug 2015 @ 1314 JSJ https://www.flickr.com/photos/jsjgeology/21145226344 Photo of Grotto Geyser's 1:14 PM-onward eruption on 14 August 2015.
08 Jul 2014 @ 1430 JSJ https://www.flickr.com/photos/jsjgeology/15106150617 Photo of Grotto Geyser erupting during the mid-afternoon of 8 July 2014.
Baseline does not exist.


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