Last Known Eruption
40d 1h 21m ago

Latest Eruptions

Eruption DurationInterval
23 May 2022 @ 1000 A8d 12h 58m
14 May 2022 @ 2102 ie4d 7h 54m
10 May 2022 @ 130837m 8d 4h 29m
02 May 2022 @ 0839 ie12d 20h 45m
19 Apr 2022 @ 11546d 6h 9m
13 Apr 2022 @ 0545 ns wc8d 22h 3m
04 Apr 2022 @ 0742 ie wc69d 6h 42m
25 Jan 2022 @ 0000 A6d 18h 53m
18 Jan 2022 @ 0507 ie wc4d 15h 55m
13 Jan 2022 @ 131232m 9d 1h 5m
04 Jan 2022 @ 1207 ie wc16d 7h 45m
19 Dec 2021 @ 0422 wc9d 15h 0m
09 Dec 2021 @ 1322 ie wc11d 2h 9m
28 Nov 2021 @ 1113 wc7d 3h 10m
21 Nov 2021 @ 0803 ns wc12d 14h 16m
08 Nov 2021 @ 1747 ? ie wc14d 18h 47m
25 Oct 2021 @ 0000 A3d 2h 32m
21 Oct 2021 @ 2128 wc3d 14h 22m
18 Oct 2021 @ 0706 ns wc3d 13h 51m
14 Oct 2021 @ 171539m 3d 23h 3m
10 Oct 2021 @ 181235m 5d 18h 12m
05 Oct 2021 @ 0000 A12d 2h 34m
22 Sep 2021 @ 212637m 4d 8h 35m
18 Sep 2021 @ 125137m 4d 20h 26m
13 Sep 2021 @ 1624:1734m 0s 2d 9h 10m 22s
11 Sep 2021 @ 0713:55~28m 3d 15h 17m
07 Sep 2021 @ 155639m 4d 21h 30m
02 Sep 2021 @ 182626m 2d 13h 18m
31 Aug 2021 @ 0508 wc3d 16h 5m
27 Aug 2021 @ 130331m 3d 10h 30m
24 Aug 2021 @ 0233 wc6d 3h 25m
17 Aug 2021 @ 230834m 5d 5h 44m
12 Aug 2021 @ 172433m 2d 19h 32m
09 Aug 2021 @ 2152 wc3d 5h 29m
06 Aug 2021 @ 162336m 5d 20h 54m
31 Jul 2021 @ 192930m 3d 17h 49m
28 Jul 2021 @ 0140 A wc4d 18h 43m
23 Jul 2021 @ 065729m 4d 6h 57m
19 Jul 2021 @ 0000 A2d 11h 49m
16 Jul 2021 @ 121132m 5d 22h 12m
10 Jul 2021 @ 135936m 5d 1h 52m
05 Jul 2021 @ 12073d 14h 14m
01 Jul 2021 @ 2153 ns4d 8h 19m
27 Jun 2021 @ 133432m 7d 5h 0m
20 Jun 2021 @ 083437m 7d 14h 40m
12 Jun 2021 @ 175428m 4d 16h 54m
08 Jun 2021 @ 0100 A5d 15h 20m
02 Jun 2021 @ 0940 ie wc16d 8h 9m
17 May 2021 @ 0131 ie wc6d 23h 34m
10 May 2021 @ 0157 wc8d 1h 57m
02 May 2021 @ 0000 ? A5d 16h 53m
26 Apr 2021 @ 0707 wc7d 8h 24m
18 Apr 2021 @ 2243 wc82d 1h 15m
26 Jan 2021 @ 2028 wc83d 3h 47m
04 Nov 2020 @ 1641 ie wc5d 2h 36m
30 Oct 2020 @ 1505 ie wc53d 16h 20m
06 Sep 2020 @ 2245 E6d 22h 4m
31 Aug 2020 @ 0041 ie wc20d 17h 46m
10 Aug 2020 @ 0655 wc1y 289d 20h 53m
25 Oct 2018 @ 1002 wc6d 20h 22m
18 Oct 2018 @ 1340 ie wc7d 13h 36m
11 Oct 2018 @ 0004 E4d 3h 0m
06 Oct 2018 @ 2104 E6d 5h 30m
30 Sep 2018 @ 1534 E3d 7h 27m
27 Sep 2018 @ 080733m 5d 9h 25m
21 Sep 2018 @ 2242 wc4d 11h 18m
17 Sep 2018 @ 1124 E3d 12h 40m
13 Sep 2018 @ 2244 E18d 15h 12m
26 Aug 2018 @ 0732 wc3d 13h 4m
22 Aug 2018 @ 182835m 5d 6h 34m
17 Aug 2018 @ 1154 E10d 6h 59m
07 Aug 2018 @ 0455 wc3d 10h 11m
03 Aug 2018 @ 1844 E4d 9h 56m
30 Jul 2018 @ 084837m 8d 9h 42m
21 Jul 2018 @ 230634m 8d 20h 27m
13 Jul 2018 @ 0239 wc5d 5m
08 Jul 2018 @ 0234 E6d 9h 17m
01 Jul 2018 @ 171734m 6d 8h 48m
25 Jun 2018 @ 0829 ns38m 11d 4h 19m
14 Jun 2018 @ 0410 wc7d 14h 52m
06 Jun 2018 @ 131832m 75d 21h 14m
22 Mar 2018 @ 1604 E3d 10h 9m
19 Mar 2018 @ 0555 wc5d 16h 11m
13 Mar 2018 @ 1344 E7d 15h 20m
05 Mar 2018 @ 2124 E4d 11h 50m
01 Mar 2018 @ 0934 E4d 4h 30m
25 Feb 2018 @ 0504 E6d 4h 30m
19 Feb 2018 @ 0034 E2d 21h 40m
16 Feb 2018 @ 0254 E5d 20h 40m
10 Feb 2018 @ 0614 E6d 4h 0m
04 Feb 2018 @ 0214 E4d 11h 51m
30 Jan 2018 @ 142332m 4d 21h 29m
25 Jan 2018 @ 1654 E6d 12h 30m
19 Jan 2018 @ 0424 E7d 13h 40m
11 Jan 2018 @ 1444 E11d 9h 46m
31 Dec 2017 @ 0458 wc4d 11h 4m
26 Dec 2017 @ 1754 E10d 18h 50m
15 Dec 2017 @ 2304 E11d 18h 30m
04 Dec 2017 @ 0434 E10d 15h 50m
23 Nov 2017 @ 1244 E6d 12h 10m

Interval Statistics

Interval Count100
Min2d 9h 10m
Max1y 289d 20h 53m
Mean16d 11h 36m
Median6d 48m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
22279 02 Jul 2022 @ 0707 --- EmilyW No eruption yet. Water from bottom vent to the river. Perhaps overnight
22190 29 Jun 2022 @ 0527 --- JimS No eruption yet. Angle marathon.
22134 26 Jun 2022 @ 1050 --- Tara No eruption yet, seems like the same old ~50 minute cycles with no water in Mortar. River is now low enough to expose the gravel bar below Bottom Vent's runoff channel.
22022 18 Jun 2022 @ 1703 --- RMichaels No eruption yet. Angle still on. River level still high.
21992 16 Jun 2022 @ 1045 --- Tara No eruption yet.
21972 13 Jun 2022 @ 1414 --- Tara No eruption yet, Firehole level is high enough that there is water about halfway up Bottom Vent's runoff channel.
21956 12 Jun 2022 @ 1527 --- Graham No eruption yet. River higher than yesterday.
21927 11 Jun 2022 @ 1455 --- Graham No eruption yet. River level still covering gravel bar rocks.
21881 10 Jun 2022 @ 0659 --- SteveO No eruption yet.
21856 09 Jun 2022 @ 0658 --- JimS No eruption yet.
21824 08 Jun 2022 @ 0932 --- JimS No eruption yet.
21804 07 Jun 2022 @ 0730 --- Darcie No eruption yet
21779 06 Jun 2022 @ 1204 --- Graham No eruption yet. River level higher than its been in last 2 weeks.
21736 05 Jun 2022 @ 0814 --- Graham No eruption yet.
21717 04 Jun 2022 @ 1025 --- Detour66 Near constant spouting from 3 vents on Fan, increasing is height from 6 inches to over 3 ft.
21680 03 Jun 2022 @ 0610 --- JimS No eruption yet.
21677 02 Jun 2022 @ 2138 --- Tara Unattended.
21649 02 Jun 2022 @ 0616 --- JimS No eruption yet
21623 01 Jun 2022 @ 0614 --- JimS No eruption yet.
21591 31 May 2022 @ 0616 --- JimS No eruption yet
21580 30 May 2022 @ 0950 --- aferrara Snow even across the boardwalk, angle ie, probably no overnight eruption, will delete if someone thinks otherwise.
21577 29 May 2022 @ 2000 29 May 2022 @ 2100 RMichaels Angle pretty much on the entire time. Many River coughs (River on and off quickly). Gold was starting almost simultaneously with River. Generally disorganized. Did not see water levels come up in Bottom Vent or Lower Mortar during this period of time
21565 29 May 2022 @ 0900 --- Dan A Unattended, no eruption yet.
21559 28 May 2022 @ 1648 --- Dan A Unattended
21544 28 May 2022 @ 1007 --- Dan A No eruption yet, short cycles with angle always on continues
21518 26 May 2022 @ 1557 26 May 2022 @ 1711 Ben VL Angle mode with short cycles. Brief instances where water levels look decent every so often.
21392 20 May 2022 @ 1920 --- Tara Unattended. Long cycles most of the afternoon.
21143 01 May 2022 @ 1850 --- RMichaels Still no eruption since 4-19-22.
21113 27 Apr 2022 @ 2020 --- RMichaels No eruption yet.
21087 26 Apr 2022 @ 1405 --- DanS No eruption yet
21041 19 Apr 2022 @ 1130 --- steve F&M was quiet about 1100 when I passed to look at Morning Glory. On return about 1108 Bottom vent was active and was occasionally joined by Lower Mortar. River came on about 1110 and the first splash seen in Main Vent was at 1112. For about 20 minutes there were occasional splashes in Main Vent, River was turning on and off and on and off. No activity from High or Gold. After AJ arrived we walked away and were about 2/3 of the way to Castle before AJ called F&M. All of this occurred in blowing snow storm. Sigh...
20967 09 Apr 2022 @ 1333 --- mhreed Appears to be in Angle marathon mode.
20745 21 Jan 2022 @ 1635 --- BrandonC No signs of eruption yet
20750 20 Jan 2022 @ 1740 --- BrandonC No eruption yet
20660 10 Jan 2022 @ 2036 --- K.Cooper Possible eruption time, ie, at this time. Steam coming from the right location (mostly right location at least), steam drifting in from the right. It is a possible eruption but due to the darkness, as well as the possibility of this being a post eruptive Grand, I am leaving as a note for now.
20600 04 Dec 2021 @ 1613 --- Betty Lots of steam from the correct position, though windblown. Not sure it is an eruption.
20236 31 Oct 2021 @ 0919 --- cb no overnight eruption. boardwalks dry, angle on but Mortar catch basin still has water.
20230 30 Oct 2021 @ 1725 --- DanS No eruption. Unattended.
20221 30 Oct 2021 @ 1430 --- DanS Has not erupted. Activity switched from lower Mortar to Fan around 1355.
20215 30 Oct 2021 @ 0920 --- User34 Catchbasins on Mortar are full, and there are fresh flow channels in the gravel in Main's line of fire. Angle is in marathon
20208 29 Oct 2021 @ 1645 --- DanS No eruption as of 1645
20187 29 Oct 2021 @ 1055 --- DanS Confirm no eruption yet.
20183 29 Oct 2021 @ 0920 --- aferrara Does not appear to have erupted overnight. I welcome a second opinion if anyone else comes out this way.
20164 28 Oct 2021 @ 1747 --- DanS No eruption yet. Unattended.
20157 28 Oct 2021 @ 1035 --- DanS No eruption yet.
20153 27 Oct 2021 @ 1725 --- DanS No eruption yet. Unattended. Cycling with some nice action in lower Mortar.
20152 27 Oct 2021 @ 1638 --- DanS YNP crew replacing signs for F&M
20077 22 Oct 2021 @ 0840 --- Tara Area wet, catchbasins full
20076 21 Oct 2021 @ 1905 --- Tara Unattended.
20069 21 Oct 2021 @ 0845 --- Tara No signs of recent eruption
20014 17 Oct 2021 @ 0940 --- Tara No sign of recent eruption.
19942 10 Oct 2021 @ 0240 --- Dan A Came down to F&M in time to check on it and saw upper mortar surging slightly over the cone with water coming out the crack. It had several of these surges. Likely the end of an event cycle. The next event cycle whenever that is will probably result in an eruption. That is probably not guaranteed though.
19940 09 Oct 2021 @ 0712 --- Dan A Good news everybody fan and mortar didn’t erupt overnight.
19936 08 Oct 2021 @ 0801 --- Dan A No eruption overnight
19886 05 Oct 2021 @ 0812 --- Darcie Erupted overnight/early morning. Catch basins are full, and boardwalk and trail are wet
19862 03 Oct 2021 @ 0752 --- ddshepard No eruption overnight
19860 02 Oct 2021 @ 0730 02 Oct 2021 @ 1823 ddshepard No eruption yet. Continued pattern of this interval of mostly weak Regular Cycles with occasional better ones with variable water levels
19845 02 Oct 2021 @ 0649 --- SteveO No eruption yet, left unattended.
19823 01 Oct 2021 @ 0756 --- Brian No overnight eruption
19820 30 Sep 2021 @ 1940 --- Tara Unattended.
19796 29 Sep 2021 @ 2045 --- Tara Unattended.
19773 28 Sep 2021 @ 2035 --- Tara Unattended
19732 25 Sep 2021 @ 2300 --- Tara Unattended.
19681 22 Sep 2021 @ 0656 --- Graham No eruption yet.
19679 21 Sep 2021 @ 1938 --- Brian Unattended
19671 21 Sep 2021 @ 0655 --- Graham No eruption yet.
19639 18 Sep 2021 @ 0651 --- Graham No eruption yet.
19629 17 Sep 2021 @ 0652 --- Graham No eruption overnight
19628 16 Sep 2021 @ 2320 --- Tara Unattended. Still in Angle mode
19595 16 Sep 2021 @ 0657 --- Graham No eruption overnight.
19412 10 Sep 2021 @ 0643 --- Graham No eruption yet. No Angle either!
19344 07 Sep 2021 @ 0545 --- hkoenig no overnight eruption.
19325 06 Sep 2021 @ 0555 --- hkoenig Angle!! And no eruption overnight
19323 05 Sep 2021 @ 2047 --- Tara Unattended, still Angle marathon
19312 05 Sep 2021 @ 0654 --- Graham No evidence of an eruption yet.
19161 30 Aug 2021 @ 0925 --- Tara No eruption yet, catchbasins and boardwalk dry.
19095 27 Aug 2021 @ 0525 --- Dan A No eruption yet
19003 23 Aug 2021 @ 0551 --- Dan A No eruption yet
18982 22 Aug 2021 @ 0549 --- Dan A No eruption yet.
18972 21 Aug 2021 @ 0637 --- Dan A No eruption yet
18950 17 Aug 2021 @ 0502 --- Dan A No eruption yet
18947 16 Aug 2021 @ 0558 --- JimS No eruption yet.
18939 15 Aug 2021 @ 0617 --- JimS No eruption yet.
18879 10 Aug 2021 @ 0023 --- deanl erupted overnight. see my A time from 8/9.
18844 06 Aug 2021 @ 0620 --- JimS No eruption yet.
18835 05 Aug 2021 @ 0552 --- JimS No eruption yet.
18833 04 Aug 2021 @ 2110 --- Brian Unattended as of 2110
18820 04 Aug 2021 @ 0553 --- JimS No eruption yet.
18566 21 Jul 2021 @ 2304 --- William unattended
18518 19 Jul 2021 @ 0825 --- deanl Fan & Mortar are very quiet and the boardwalk is wet. They likely erupted overnight
18489 15 Jul 2021 @ 2000 --- Tara Unattended, storm moving in
18427 14 Jul 2021 @ 2100 --- Tara Unattended
18314 09 Jul 2021 @ 0601 --- JimS No eruption yet.
18309 08 Jul 2021 @ 0607 --- JimS No eruption yet.
18253 03 Jul 2021 @ 0556 --- JimS BV sending water nearly to the river and LM splashing. Lots of steam from MV.
18214 01 Jul 2021 @ 0607 --- JimS No eruption yet.
18109 27 Jun 2021 @ 0548 --- JimS No eruption overnight.
18107 26 Jun 2021 @ 2211 --- William unattended
18100 26 Jun 2021 @ 0551 --- JimS No eruption yet.
18068 24 Jun 2021 @ 0630 24 Jun 2021 @ 0659 JimS Disorganized splashing followed by Angle solo.
EntrySourceLinkComment
13 Sep 2021 @ 1624 Tara https://youtu.be/SriD_M5k2hQ Video of eruption by Tara Cross.
27 Jun 2021 @ 1334 Tara https://youtu.be/yFbVqS3i8yc Video of eruption by Tara Cross.
20 Jun 2021 @ 0834 Tara https://youtu.be/27nF0KIAt9s Video of eruption by Tara Cross.
02 Sep 2021 @ 1826 Tara https://youtu.be/hzkdexYf-Yc Video of eruption by Tara Cross.
24 Aug 2021 @ 0233 Tara https://youtu.be/kohfkNVhvDI?t=525 overnight webcam capture showing Fan and Mortar steam cloud at 0233
09 Aug 2021 @ 2152 Tara https://youtu.be/pAbQFfYkE6I?t=71 overnight webcam capture showing Fan and Mortar steam cloud at 2152
24 Aug 2021 @ 0233 JoeN https://youtu.be/NTOAh5LI5Ns F&M video
02 Jun 2021 @ 0940 JoeN https://youtu.be/SzszlKWaG9k F&M video
26 Apr 2021 @ 0707 JoeN https://i.imgur.com/78YCoLM.png start and in progress
26 Apr 2021 @ 0707 JoeN https://i.imgur.com/78YCoLM.png Start and in progress
18 Apr 2021 @ 2243 JoeN https://youtu.be/cEMy4JNZ6EE Fan & Mortar ~2243:50 Bonus Lion and Aurum
26 Jan 2021 @ 2028 JoeN https://youtu.be/EFhzZMlIcPw Fan & Mortar video
26 Jan 2021 @ 2028 K.Cooper https://youtu.be/aTzHnPw7yc8 Few minutes of F&M, video by Linda Gangi.
26 Jan 2021 @ 2034 ltgangi https://youtu.be/aTzHnPw7yc8 F&M
30 Oct 2020 @ 1505 JarnoO https://www.youtube.com/watch?v=2poGwom5GkM As seen from the webcam.
31 Aug 2020 @ 0041 JoeN https://youtu.be/9YPisj8Lx-g F&M as seen from NPS Camera
10 Aug 2020 @ 0710 JoeN https://www.youtube.com/watch?v=R5yPZ8CcfEg CraigC video
10 Aug 2020 @ 0655 JoeN https://www.youtube.com/watch?v=R5yPZ8CcfEg CraigC video
10 Aug 2020 @ 0655 JoeN https://youtu.be/MqyYPz67QZE F&M replay
06 Jun 2018 @ 1318 JSJ https://www.youtube.com/watch?v=V6v-pWJqTwY#t=5m47s Clips 18-27 of this video compilation (= time stamp 5:47 to the end) show some of Fan Geyser’s 1:18 to 1:52 PM major eruption on 6 June 2018.
BaselineDistance (ft)Description
Rock 100Both markers are on a rock behind the benches on the upstream side of the path