Last Known Eruption
21y 10d 15h 41m ago

Latest Eruptions

Eruption DurationInterval
14 Sep 2000 @ 1007 min64d 2m
12 Jul 2000 @ 10056d 22h 31m
05 Jul 2000 @ 113423h 14m
04 Jul 2000 @ 12207d 20h 39m
26 Jun 2000 @ 154135d 19h 44m
20 Jun 2000 @ 195716d 9h 11m
04 Jun 2000 @ 10464m 4d 18h 26m
30 May 2000 @ 1620 maj10m 234d 5h 30m
09 Oct 1999 @ 105019h 52m
08 Oct 1999 @ 14581d 1h 36m
07 Oct 1999 @ 132223h 42m
06 Oct 1999 @ 134020h 30m
05 Oct 1999 @ 17102014d 7h 23m
21 Sep 1999 @ 09474m 1d 23h 25m
19 Sep 1999 @ 10221d 23h 57m
17 Sep 1999 @ 10252m 6d 23h 52m
10 Sep 1999 @ 10338d 20h 14m
01 Sep 1999 @ 14195d 2h 42m
27 Aug 1999 @ 113710m 1d 22h 37m
25 Aug 1999 @ 130011d 18h 11m
13 Aug 1999 @ 18498h 8m
13 Aug 1999 @ 10418d 12h 21m
04 Aug 1999 @ 222010h 30m
04 Aug 1999 @ 11504d 13m
31 Jul 1999 @ 11371d 23h 10m
29 Jul 1999 @ 12274-5m2d 2h 10m
27 Jul 1999 @ 10174m 3d 17h 50m
23 Jul 1999 @ 162774d 10h 7m
10 May 1999 @ 06201d 10h 20m
08 May 1999 @ 2000230d 4h 24m
20 Sep 1998 @ 153617d 4h 30m
03 Sep 1998 @ 11065m 17d 23h 25m
16 Aug 1998 @ 114114d 4m
02 Aug 1998 @ 11373m 10d 23h 58m
22 Jul 1998 @ 1139 A1d 42m
21 Jul 1998 @ 1057 A23h 57m
20 Jul 1998 @ 1100 ie3d 15h 52m
16 Jul 1998 @ 1908 ie10d 7h 14m
06 Jul 1998 @ 11548d 21h 34m
27 Jun 1998 @ 14205m 3d 23h 10m
23 Jun 1998 @ 15104d 25m
19 Jun 1998 @ 14455m
19 Jun 1998 @ 144011m
19 Jun 1998 @ 142973d 44m
07 Apr 1998 @ 1345198d 13h 57m
20 Sep 1997 @ 23482d 20h 33m
18 Sep 1997 @ 031526d 8h 20m
22 Aug 1997 @ 18554d 22h 56m
17 Aug 1997 @ 1959 min~55d 44m
12 Aug 1997 @ 191513d 46m
30 Jul 1997 @ 182918d 8h 42m
12 Jul 1997 @ 094714m 11h 56m
11 Jul 1997 @ 21518h 36m
11 Jul 1997 @ 13156d 22h 23m
04 Jul 1997 @ 14523y 8h 57m
05 Jul 1994 @ 0555 ns14d 13h 15m
20 Jun 1994 @ 164035m 10d 7h 12m
10 Jun 1994 @ 092824m 10d 14h 54m
30 May 1994 @ 18343d 11h 10m
27 May 1994 @ 0724397d 19h 54m
19 May 1994 @ 113012d 1h 30m
07 May 1994 @ 100012d 7h 43m
25 Apr 1994 @ 0217210d 15h 36m
26 Sep 1993 @ 104121d 2h 2m
05 Sep 1993 @ 08391d 19h 9m
03 Sep 1993 @ 13301d 22h 45m
01 Sep 1993 @ 14456d 45m
26 Aug 1993 @ 14003m 1d 3h 48m
25 Aug 1993 @ 10123d 17h 47m
21 Aug 1993 @ 16253d 40m
18 Aug 1993 @ 1545 A4d 5h 57m
14 Aug 1993 @ 09482d 22h 16m
11 Aug 1993 @ 11321d 2m
10 Aug 1993 @ 11301d 1h 50m
09 Aug 1993 @ 0940 ie8d 16h 40m
31 Jul 1993 @ 17005d 6h 30m
26 Jul 1993 @ 103028d 1h 36m
28 Jun 1993 @ 08545m 5d 50m
23 Jun 1993 @ 08045m 359d 16h 39m
28 Jun 1992 @ 1525 ie357d 4h 18m
07 Jul 1991 @ 1107 maj1y 18d 23h 2m
18 Jun 1990 @ 12052m 35m
18 Jun 1990 @ 113010m 334d 18h 30m
18 Jul 1989 @ 1700>10m 24d 1h 19m
24 Jun 1989 @ 15412h 1m
24 Jun 1989 @ 1340 ie>5m 13d 20h 10m
10 Jun 1989 @ 1730 maj1h 4m
10 Jun 1989 @ 1626 maj13m
10 Jun 1989 @ 1613 maj20m
10 Jun 1989 @ 1553 maj22m
10 Jun 1989 @ 1531 maj25m
10 Jun 1989 @ 1506 maj21m
10 Jun 1989 @ 1445 maj20m
10 Jun 1989 @ 1425 maj21m
10 Jun 1989 @ 1404 maj12d 3m
29 May 1989 @ 1401 maj57m
29 May 1989 @ 1304 maj12m
29 May 1989 @ 1252 maj19m
29 May 1989 @ 1233 maj18m
29 May 1989 @ 1215 maj22m

Interval Statistics

Interval Count100
Min5m
Max3y 8h 57m
Mean41d 6h 13m
Median4d 12h 11m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
17454 04 Jun 2021 @ 1815 --- MAB Dry but steamy
4727 02 Oct 2000 @ 1800 --- research-mab 10/02/2000 Dark Cavern lots of minors separated by 10-15 minutes
5385 01 Feb 1995 @ 1800 --- research-mab 02/01/1995 It seems the disturbance activity is basin wide! Lava Pool, Arsenic, Moxie, Pinto, Constant, Scummy Pool, Dark Cavern and Ledge all seem affected. .... Dark Cavern is high pressure steam with occasional water. {no time noted}
4715 24 Jun 1990 @ 1800 --- research-mab 6/24/1990 Dark Cavern has small eruptions that reach or slightly exceed the rim about every two minutes. Each eruption lasts about one minute. After watching for ½ hour I saw one of its major eruptions that lasted about 4 minutes. Erupted vigorously from both vents & cleared the rim by 8-10 feet.
4699 04 Jul 1988 @ 1800 --- research-mab 7/4/1988 Dark Cavern Geyser is having eruptions that clear the top of the vent by 4-10 ft. The most spectacular I’ve seen.
7616 11 Feb 1984 @ 1800 --- research-mab 02/11/1984 Dark Cavern Geyser Active.
4648 22 Sep 1981 @ 1900 --- research-mab 9/22/1981 I caught some sort of super eruption out of Dark Cavern lasting ~ 4-5 minutes with water bursts going to at least 20 feet high. I saw just the end of one 3 days ago but only saw bursts to ~ 8-10 feet so I thought it was just a large regular eruption. The roaring noise is clearly audible up at the museum (even on very windy days like today) where normal eruptions cannot be heard in the archway. This is the 3rd such eruption that I know of …. the first being ~ midnight a week ago that Fred heard.
5085 24 Jun 1980 @ 1800 --- research-mab 06/24/1980 Dark Cavern had a 15 minute interval between eruptions.
5078 01 Jun 1980 @ 1800 --- research-mab 06/01/1980 Dark Cavern was quite forceful.
5094 02 Apr 1978 @ 1800 --- research-mab 04/02/1978 Dark Cavern is having gentle eruptions about every 5 min.
5108 28 Jun 1977 @ 1800 --- research-mab 06/28/1977 Dark Cavern geyser has become less active, with eruptions every 5-10 minutes rather than the 2-3 minutes noted before. The geyser also appears to be less powerful. PCS
5207 23 Sep 1976 @ 1800 --- research-mab 09/23/1976 Dark Cavern has been erupting with unusual force the last 4 days. Eruptions are generally shorter but sprays go all the way over the ridge & into the Valentine Alcove. The interval between eruptions is slightly longer.
5236 09 Sep 1976 @ 1800 --- research-mab 09/09/1976 Dark Cavern was observed for a period of about 40 minutes last night. It was found that the interval between eruptions was nearly always 7 ½ minutes with eruptions lasting between 5 & 6 minutes. Nearly half of the eruption time was taken up by minor play, with a forceful blast of water lasting around 3 minutes.
5862 28 Jun 1976 @ 1550 28 Jun 1976 @ 1610 research-mab 06/28/1976 The basin was very active from about 3:50 to 4:10. Dark Cavern sustained an eruption for about 4 min. Eruption was unusually powerful, with sprays bursting way over the rock. Arsenic Geyser erupting constantly during above interval. “Frijole” Geyser began eruption when Big Whirligig did. Was mainly steam (est, 4’ hi) Blue erupting throughout this time. Feisty erupting during this time.
5612 06 Aug 1975 @ 1800 --- research-mab 08/06/1975 Dark Cavern seems to have almost constant action lately.
5601 15 Jul 1975 @ 1800 --- research-mab 07/15/1975 Dark Cavern observed having minor eruptions of 30-50 sec duration every minute or so.
5814 08 Sep 1974 @ 1800 --- research-mab 09/08/1974 Dark Cavern continues the steam (no water) eruptions
5704 24 May 1974 @ 1800 --- research-mab 05/24/1974 Dk Cavern seen in eruption often during last few days.
5703 22 May 1974 @ 1800 --- research-mab 05/22/1974 Dark Cavern was noted to be in eruption numerous times throughout the day.
6202 17 Oct 1973 @ 1800 --- research-mab 10/17/1973 Dark Cavern: interval is irregular and sometimes shorter than as seen on October 1. R Hutchinson
6198 01 Oct 1973 @ 1700 --- research-mab 10/01/1973 Porcelain Basin 5:00 pm Dark Cavern interval shortening to about 20 min more water than recent and steam not as powerful.
6104 28 Aug 1973 @ 1800 --- research-mab 08/28/1973 Dark Cavern still with violent steam action some muddy water erupting from it. {no specific time}
6089 27 Aug 1973 @ 1800 --- research-mab 08/27/1973 Dark Cavern still active (in similar manner as this afternoon) but with less intensity. {no specific time}
5966 16 Apr 1973 @ 1800 --- research-mab 04/16/1973 Dark Cavern: most of the eruptions during the past few weeks have been noted to have no runoff even though they may be up to full height. Also, the durations, while not accurately measured, have been noticeably shorter.
5924 15 Mar 1973 @ 1800 --- research-mab 03/15/1973 No eruptions were observed from Dark Cavern today in spite of the frequent periods of minor play.
5909 10 Mar 1973 @ 1800 --- research-mab 03/10/1973 Dark Cavern: one eruption timed. Totally play 6:00 minutes, vigorous & noisy phase of eruption (after NW vent was covered) lasted 3:49, and only approximately 20 seconds were required for the water in the main vent to drain. Rick H
6484 11 Sep 1972 @ 1200 --- research-mab 09/11/1972 Bear Den, Dark Cavern, Africa. L. Whirligig, Blue, Fireball & Arsenic all have been observed in eruption this morning. {generic a.m. time}
6491 15 May 1972 @ 1800 --- research-mab 05/15/1972 Dark Cavern Geyser – minor spitting and sputtering every few minutes; major eruption once or twice an hour temp during minor play 200º
6594 09 Sep 1970 @ 1600 --- research-mab 09/09/1970 Dark Cavern erupted and played longer than usual. {no specific time - listed after ledge in log}
7673 12 Aug 1970 @ 1800 --- research-mab 08/12/1970 Much activity in Porcelain in late pm (6-7) Arsenic, Fireball, and Fan went off in succession. 8/12/1970 Dark Cavern had extended eruption also.
7190 17 Aug 1966 @ 1600 --- research-mab 08/17/1966 Dark Cavern Took C&F (USGS) to watch (4pm) it and several cycles in a row were very weak – steam ceased without receiving water – Does Ledge have a weakening effect? Had been very strong before Ledge erupted.
7124 17 Jul 1966 @ 0800 --- research-mab 07/17/1966 Dark Cavern – Water has bluish cast in a.m.
6897 27 Jun 1965 @ 1800 --- research-mab 06/27/1965 Dark Cavern continues to increase its water supply each day. A crack in its drainage channel continues to increase in size & overflow.
6880 17 Jun 1965 @ 1800 --- research-mab 06/17/1965 Dark Cavern – I have watched it several times for as long as ½ hour at a time. Every several minutes the steam pressure will increase and then subside as it did last year. However, this year (so far) there is no water present.
6785 23 Oct 1964 @ 1800 --- research-mab 10/23/1964 Dark Cavern is apparently fully restored.
6781 18 Oct 1964 @ 1800 --- research-mab 10/18/1964 Dark Cavern appears fully restored.
6777 17 Oct 1964 @ 1800 --- research-mab 10/17/1964 Dark Cavern has more water than yesterday. The west vent still shoots only steam (maybe that’s all it ever did). Very noisy.
6766 16 Oct 1964 @ 1800 --- research-mab 10/16/1964 Dark Cavern has regained some water but is not yet fully restored.
6744 09 Oct 1964 @ 1800 --- research-mab 10/09/1964 Dark Cavern has lost its water & just puffs steam.
6638 21 Jun 1964 @ 1500 --- research-mab 06/21/1964 Dark Cavern 3:00p Bill Lewis observed this for ~ 30 min and found that it had a very nearly regular 10 min cycle. To Mr. Lewis’ knowledge this is the only geyser in the park which starts with a steam phase (rather than H20).
10804 01 Jul 1933 @ 0000 --- research-mab Report for June 1933: Hillside Geyser – eruptions of 10-15 ft at irregular intervals
10813 19 Sep 1931 @ 0000 --- research-mab Hillside Geyser Sept 1-4 Played at irregular intervals 4-5 times per day. Height 10-15 ft. Duration – 40 sec. Sept 5-19 No eruptions. Some water running from vent continuously.
10821 05 Aug 1931 @ 0000 --- research-mab Aug 1931 Report: Hillside Geyser Aug 5 At irregular intervals 1 min 20 ft.
10820 04 Aug 1931 @ 0000 --- research-mab Aug 1931 Report: 8/4/1931 Hillside Geyser At 2 hr intervals all day 1 min 20 ft.
No attachments for this geyser.
Baseline does not exist.