Last Known Eruption
1d 14h 2m ago

Latest Eruptions

Eruption DurationInterval
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 13h 3m
24 Aug 2021 @ 0000 A6d 52m
17 Aug 2021 @ 230834m 5d 5h 44m
12 Aug 2021 @ 172433m 2d 18h 24m
09 Aug 2021 @ 2300 A3d 6h 37m
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
17 Nov 2017 @ 0034 E6d 4h 25m
10 Nov 2017 @ 2008:40 E5d 18h 5m 0s
05 Nov 2017 @ 0203:40 E5d 4h 51m
30 Oct 2017 @ 2212 wc7d 7h 53m
23 Oct 2017 @ 1418:40 E8d 3h 24m
15 Oct 2017 @ 10546d 10h 54m
09 Oct 2017 @ 0000 wc5d 14h 44m
03 Oct 2017 @ 0916 ns wc5d 3h 2m
28 Sep 2017 @ 0614 ns wc7d 8h 5m
20 Sep 2017 @ 2208:40 E14d 11h 6m
06 Sep 2017 @ 110229m 5d 14h 56m
31 Aug 2017 @ 200634m 9d 6h 23m
22 Aug 2017 @ 134333m 10d 49m
12 Aug 2017 @ 1254~31m 9d 16h 25m
02 Aug 2017 @ 202929m 2d 14h 5m
31 Jul 2017 @ 062434m 11d 14h 57m
19 Jul 2017 @ 152734m 10d 9h 22m
09 Jul 2017 @ 060533m 9d 12h 41m
29 Jun 2017 @ 1723 E9d 11h 42m
20 Jun 2017 @ 0541 wc4d 13h 34m
15 Jun 2017 @ 160729m 103d 3h 28m
04 Mar 2017 @ 1138 E24d 15h 40m
07 Feb 2017 @ 1958 E19d 1h 50m

Interval Statistics

Interval Count100
Min2d 9h 10m
Max1y 289d 20h 53m
Mean17d 39m
Median6d 2h 26m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
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.
17943 20 Jun 2021 @ 1200 --- WillBoekel system showing normal signs of an eruption previous. 3.5hrs after eruption vents of fan drying and turning white. only a slight waft of steam from upper mortar.
17936 20 Jun 2021 @ 0542 --- JimS No eruption yet.
17900 19 Jun 2021 @ 0557 --- JimS No eruption yet. Vents are steaming. BV splashing.
17894 18 Jun 2021 @ 2230 --- William unattended
17896 18 Jun 2021 @ 1424 18 Jun 2021 @ 1926 Polly Overall, F&M were having long cycles. Bottom Vent and Lower Mortar showed water splashing on many cycles. Upper Mortar grumbled or roared on some of the cycles, and water was seen occasionally. Fan had better water levels than were seen on previous days. Angle often came on or splashed before Gold came on. Main Vent was steamy at times, and we heard a couple of roars. Only one small splash in MV was seen.
17878 18 Jun 2021 @ 0552 --- JimS No eruption yet. Just winding up a cycle now.
17741 13 Jun 2021 @ 0950 --- JimS Bottom vent was erupting to the river at this time.
17732 12 Jun 2021 @ 1510 12 Jun 2021 @ 1644 Graham Here is the garbage activity that preceded the event cycle and subsequent eruption. 1510 RV off, AV ie. 1517 everything coughed on and off. 1519 everything coughed on and off, AVstill ie. 1528 everything on. 1543 RV off, and back on several times with AV ie. 1553 RV off, AV ie. 1604 AV off. 1614 AV on. 1620 RV and AV on. 1621 GV on. 1640 RV off, AV ie. 1644 RV cough.
17697 12 Jun 2021 @ 1005 12 Jun 2021 @ 1027 Polly A already off, 1005 RH, 1006 G 1010 G pause 1015 BV spritzing, brief low water LM !1017 Angle on full! 1020 RH back on AC
17690 12 Jun 2021 @ 0625 12 Jun 2021 @ 0731 JimS All cycles disorganized.
17686 11 Jun 2021 @ 2100 11 Jun 2021 @ 2130 William continued disorganization
17675 11 Jun 2021 @ 1907 --- Graham Garbage for the last hour, short cycles, vents on in the wrong order. 1754 RV already off. 1805 AV last splash. 1810 one AV splash. 1815 RV and AV on. 1818 GV on. 1822 RV off. 1825 RV and AV on, then Gold. 1835 RV and AV off. 1840 RV, AV, and then GV on. 1854 RV off AV ie. 1904 RV  on, AV still ie.
17673 11 Jun 2021 @ 1700 --- Polly Unattended
17653 11 Jun 2021 @ 0657 --- JimS Angle solo.
17596 09 Jun 2021 @ 0659 --- CraigC blast of horizontal water in Main Vent while High and Gold splashing sporadically
17515 06 Jun 2021 @ 0950 06 Jun 2021 @ 1930 Graham No event cycles during this time. All cycles were well organized with River on before Gold on before Angle on and Angle turned off each cycle, usually within 10 minutes of River turning off. Main Vent steamed a lot but never had forced huffing or splashes. A couple of cycles had good water levels as long as 14m after Gold turned on but most did not. Upper Mortar only splashed once in the cone on the strongest cycle.
17469 05 Jun 2021 @ 0831 --- CraigC Bottom Vent ie, runoff halfway to river
17429 04 Jun 2021 @ 1034 --- CraigC Bottom Vent ie, runoff to river
17372 02 Jun 2021 @ 1010 --- JimS End of water phase
17331 01 Jun 2021 @ 1150 --- Graham Angle marathon continues.
17233 28 May 2021 @ 1900 --- Ben VL Angle. Saw some light splashing from BV this time.
17200 27 May 2021 @ 0825 27 May 2021 @ 1300 Suzanne Angle Vent continued its sporadic splashing. No good cycles seen.
17193 26 May 2021 @ 1721 --- Ben VL Angle show continues. I think F&M may have realized what month it is.
17186 25 May 2021 @ 2116 --- Ben VL Unattended. Watched for an hour ish. Been getting nothing but Angle garbage every evening when I've watched it for the last three days.
16929 27 Apr 2021 @ 0934 --- CraigC Bottom vent ie, runoff halfway to Firehole
16917 25 Apr 2021 @ 1258 --- CraigC there is some water in the upper catch basin on Mortar, probably less than half full. indication on runoff channel of Main does not confirm an eruption
16165 18 Sep 2020 @ 0740 --- CraigC Angle splashing, everything else huffing or puffing in the system
16160 18 Sep 2020 @ 0528 --- Graham Currently in garbage mode. Angle on and River turning on and off with occasional participation by Gold. 0554 River off Angle still on. All on 0606. Departed for breakfast.
16252 10 Sep 2020 @ 1300 --- Graham Water in the UM catch basins and no rain recently (snow on evening of the 7th was the last precip). Unknown when it may have erupted but water was reported present this morning. Probably from the eruption late on 6th from the monitor.
15904 31 Aug 2020 @ 0900 --- CraigC boardwalk wet between Spiteful and trees to the North. Water in Upper Mortar catch basins.
15720 24 Aug 2020 @ 0654 --- underarockphoto Heavy steam from that area on the webcam. Not enough oomph for eruption, but could be recently post eruptive...?
15513 11 Aug 2020 @ 1116 --- CraigC observed what appeared to be a regular event cycle, including 9 min full eruption of bottom vent, accompanied by much splashing in main vent with eventual normal turn on of river at 11:56 high gold at 11:58 Angle at 12:09, the vents off at 12:14
15481 10 Aug 2020 @ 0824 --- Suzanne All vents are quiet. Puddles of water still remain on boardwalk near Fan. Puddles of water around Mortar and Fan vents.
14852 02 Jul 2020 @ 1340 02 Jul 2020 @ 1429 steve Not much to see. Nothing happened in Mortar. For Fan at different times I saw river, high, gold, and angle but only for a minute or so at a time. Nothing from main vent. Nothing looked organized.
14220 19 May 2020 @ 1441 --- Janet Jones Playing whack-a-mole - didn't organize into anything worth staying for. https://www.instagram.com/p/CAZP3ucjDYj/
14132 22 Feb 2020 @ 1028 --- Art Still has snow bank between East and Main. No recent eruptions
14080 21 Jan 2020 @ 1040 --- Graham Big snow bank between East and Main Vents. No recent eruption.
13970 24 Oct 2019 @ 1339 --- steve I don’t think F&M erupted recently. There is still a full snow coat on the boardwalk and some snow patches between the boardwalk and Fan. As for Link there is also snow below Link so it can be ruled out. Maybe it was Riverside this morning.
13967 24 Oct 2019 @ 0832 --- EricZ There was a large steam cloud observed on the webcam that was in the general area of F&M. Really hard to tell, with the white skies and -2 degree temps, what it is. But we don't generally see steam at that location and the distance, angle are correct for F&M. I will attach a screenshot, captured late @ 9:10, but still seems extra steamy there. EDIT: After an in-basin observation from Steve and subsequent eruption of riverside, I would probably lean toward this steam being riverside in the mist. https://geysertimes.org/note.php?id=13970
13690 14 Sep 2019 @ 1342 14 Sep 2019 @ 1404 Polly River (& Angle) off upon arrival. BV spritz intermittent & could see the tops of int splashes in LM. 1348 R on. MV had light intermittent steam which continued. 1356 A then G on. High had some 2-3’ bursts.
13613 07 Sep 2019 @ 1150 07 Sep 2019 @ 1311 EmilyW Was on for the entire time I was there until off at 1231. Off until river back on at 1258 with some water in Mortar in between. Gold 1304 Angle 1308 On for more then it’s off. Water never there. Very bleh cycle.
13600 05 Sep 2019 @ 1209 --- Polly 1209 R/H ie. 1210 A & G intermittent. (Well into a cycle.). BV runoff channel wet/damp 1/2 way down.
13542 04 Sep 2019 @ 1618 04 Sep 2019 @ 1629 Polly On arrival, BV channel wet 1/2 way down. High had thick bursts to 2’ & Gold thick bursts to 1’. Angle appeared at 1619 (but may have started before I got there). At 1620 H & G dropped, and MV had copious steam. 1625 MV roar, 1624 audible steam Upper Mortar. 1627 H & G thick again briefly but not as tall.
13551 04 Sep 2019 @ 1115 04 Sep 2019 @ 1218 c.barwin Arrived to see a healthy jet of water coming from River, a fairly tall High Vent ie and a tallish nicely pooling Gold Vent ie, and Angle Vent was also playing. All vents waned at 1124 and finally fully turned off at 1206, except AV. During this time of quiet, MV and Mortar steamed, but not with force. All the vents turned on at 1215. Angle never fully stopped blipping. The fish are still jumping. The picnic table is still in place. Maybe next year.
13535 04 Sep 2019 @ 0730 04 Sep 2019 @ 0810 Graham River Gold and Angle on all this time. nothing special, just a long time with them all on and still on as i leave
11810 15 Jun 2019 @ 1240 15 Jun 2019 @ 1250 Polly 1240 R & A ie. 1244 R off, A continues. BV a few very light drops & mild MV steam. 1248 R/H, 1249 G & A. Very quick cycle. (My experience with spring mode is long organized cycles.) There is a very small “pool” of water immediately to the left of BV. River a bit high & somewhat muddy.
11536 03 Jun 2019 @ 0630 --- Kyle still no indication that it is ready to wake up. River seems low enough but poor water levels and "garbage" cycles dominate minor activity as it has over the last 2 weeks of occasional observation
11030 20 Apr 2019 @ 0930 20 Apr 2019 @ 1945 RMichaels Yesterday, Fan and Mortar were having short, organized cycles (and at least one event cycle with significant Main Vent splashing, which is more promising than what I usually see this time of year). Today I observed Fan and Mortar from 0930-1945. Though I left for a couple periods, I believe I only missed two cycles. Cycles today were longer and less organized than what I saw yesterday. I only saw one "event" all day: it started at 1238 and it consisted of Main Vent splashing prior to a cycle start followed by one small MV splash after River came on. Otherwise the cycle was unremarkable (no pauses, little activity from Mortar, mediocre water levels). After that, the cycles were all long (River on for 1 hour or more) and boring except for the last. The last cycle was a regular cycle, though Main Vent steamed heavily prior to River starting and Bottom Vent and Lower Mortar had higher water levels than prior cycles. River and Gold came on almost simultaneously at 1907 and had much better water levels than what I'd seen previous. High and Gold had periods of jetting up to 4-6 feet that lasted for up to a minute. Water levels waned prior to Angle on at 1923, but the sudden increase in energy was still a positive. It will be interesting to see if Fan and Mortar continues its usual spring slumber or if it's working back toward having eruptions.
10874 20 Jan 2019 @ 1435 --- Graham no ice at the splashpoint. likely dormant.
10794 25 Dec 2018 @ 1600 --- Janet Jones Snow on things - no recent eruption- photo will be on my Instagram account (YellowstoneNaturalist)
10716 04 Nov 2018 @ 0840 --- steve No overnight eruption
10707 03 Nov 2018 @ 1115 --- steve No eruption overnight
10704 02 Nov 2018 @ 1143 --- steve It appears F&M did not erupt overnight. No ice or other signs.
10699 01 Nov 2018 @ 1250 --- steve At F&M I just watched three quick junk cycles. River, then High and Gold after a few minutes, then all off after a few minutes, then maybe five minutes off before it all repeats.
10619 18 Oct 2018 @ 1340 18 Oct 2018 @ 1344 MikeG Steam visible on webcam. Too much wind to know if it's really coming from F&M.
10606 13 Oct 2018 @ 1400 --- Tara No eruption overnight.
10599 12 Oct 2018 @ 0920 --- Suzanne No eruption overnight.
10586 07 Oct 2018 @ 1830 --- William Unattended. No eruption as of 18:30
10572 06 Oct 2018 @ 0950 --- Tara No eruption overnight.
10570 05 Oct 2018 @ 1925 --- William Unattended. Had not erupted when I left at 19:25.
10565 05 Oct 2018 @ 1020 --- Tara No eruption overnight.
10505 30 Sep 2018 @ 1730 --- ThomasR Bridge and boardwalk wet. All vents quiet.
10476 27 Sep 2018 @ 0500 --- Graham No eruption yet.
10475 26 Sep 2018 @ 1950 --- William Had not erupted when I left at 19:50.
10468 26 Sep 2018 @ 1844 --- Brian Unattended
10465 26 Sep 2018 @ 1534 --- Polly Unattended
EntrySourceLinkComment
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.
06 Jun 2018 @ 1318 JSJ https://www.youtube.com/watch?v=577PNumPMvc#t=10m28s Video of Fan & Mortar Geysers' 1:18 to 1:52 PM major eruption on 6 June 2018.
17 Jul 2018 @ 2134 EmilyW https://imgur.com/z13q7vZ Webcam capture from July 17th in the first minute steam appears in the fan and mortar area on the webcam
06 Jun 2018 @ 1318 JSJ https://www.flickr.com/photos/jsjgeology/41518400070 Photo (out of 16) of Fan & Mortar Geysers' 1:18 to 1:52 PM eruption on 6 June 2018.
19 Mar 2018 @ 0555 EricZ https://www.youtube.com/watch?v=xtgCz2D1Wfw&t=14m43s Link to video review of that timeframe. Starts @ 14m 43s
31 Jul 2017 @ 0624 Tara https://youtu.be/kSklbSOYTp8 Video by Tara Cross.
31 Aug 2017 @ 2006 Tara https://youtu.be/6m2cmX6aIfw Eruption video by Tara Cross.
BaselineDistance (ft)Description
Rock 100Both markers are on a rock behind the benches on the upstream side of the path