Last Known Eruption
23y 170d 20h 59m 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 @ 10415d 11h 50m
07 Aug 1999 @ 22513d 31m
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 @ 03154d 4h 27m
13 Sep 1997 @ 2248 ie2d 19h 33m
11 Sep 1997 @ 0315 A19d 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

Interval Statistics

Interval Count100
Min5m
Max3y 8h 57m
Mean41d 6h 12m
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
29877 31 May 2000 @ 1200 --- research-mab 5/31/2000 - no time noted - Dark Cavern erupted today.
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}
30180 08 Aug 1994 @ 1200 --- research-mab 8/8/1994 - no times noted - Disturbance continues!! . I think Ledge and Dark Cavern are stuck!!
30309 22 Sep 1993 @ 1002 22 Sep 1993 @ 1034 research-mab 9/22/1993 page of Dark Cavern minor times {1002-1034} - These eruptions all strted with the main vent. The first one I watched splashed off and on for some time in the main vent before the side vent, on the left, started. Durations and intervals were a few minutes. These eruptions are much quieter & shorter and less spectacular than the loud ones noted at various times during the summer.
30337 07 Jun 1992 @ 1200 --- research-mab June 7, 1992 - no time noted - Dark Cavern active.
30318 26 Apr 1992 @ 1200 --- research-mab 4/26/1992 - no time noted - - Dark Cavern – quiet w/occasional small splashes
30511 16 May 1991 @ 1200 --- research-mab 5/16/1991 - no time noted - Dark Cavern – eruptions within crater nearly constant with only a few seconds between bursts
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.
30743 15 Sep 1989 @ 1200 --- research-mab 9/15/1989 - no time noted - Dark Cavern big eruptions well above formation
30816 26 Jul 1988 @ 1200 --- research-mab 7/26/1988 - no time noted - Dark Cavern has eruptions that clear the manganese oxide covered rocks by 5-8 feet, in addition to smaller eruptions.
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.
30900 01 Sep 1987 @ 1200 --- research-mab 9/1/1987 - no time noted - Dark Cavern continues to have impressive eruptions.
30888 23 Aug 1987 @ 1200 --- research-mab 8/23/1987 - no time noted - 8/23 cont… Dark Cavern Geyser is erupting above the rocks – reaching 4-5’ in height.
33447 09 Oct 1986 @ 1200 --- research-mab 10/09/1986 – no time noted - Dark Cavern Geyser erupted to about 3’ in height, didn’t have enough time to get an interval.
7616 11 Feb 1984 @ 1800 --- research-mab 02/11/1984 Dark Cavern Geyser Active.
31250 20 Feb 1982 @ 1200 --- research-mab February 20 1982 - no time noted - Dark Cavern Geyser 196º during a very strong eruption
31193 15 Jan 1982 @ 1200 --- research-mab January 15th, 1982 - no time noted - Dark Cavern 192º immediately after eruption, still probably having major eruptions lots of gravel & the ice formation around it indicate major eruptions
31580 27 Nov 1981 @ 1200 --- research-mab Nov 27th 1981 - no time noted - Dark Cavern 196º during eruption; water is a turbid gray; it appears to still be having super eruptions since a lot of bright reddish/orange altered tuff is being thrown from the vent.
4648 22 Sep 1981 @ 1200 --- research-mab 9/22/1981 - no time noted - 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.
31505 10 Aug 1981 @ 1200 --- research-mab Monday Aug 10, 1981 - no time noted - Dark Cavern Geyser – gray turbid water during erupt
31793 22 Sep 1980 @ 1200 --- research-mab Monday Sept 22, 1980 - no time noted - One week following the disturbance, some porcelain basin observations: Dark Cavern Geyser – water running heavily into west vent seems to drown the eruption, Gray opalescent water 202ºF ie
31730 06 Sep 1980 @ 1200 --- research-mab Sat Sept 6 1980 - no time noted - Dark Cavern Geyser - 204°F before an eruption
31675 22 Jul 1980 @ 1315 --- research-mab Porcelain report 7/22/80 Porcelain 1:15-1:30: - Dark Cavern – light steam, no eruption
5085 24 Jun 1980 @ 1800 --- research-mab 06/24/1980 Dark Cavern had a 15 minute interval between eruptions.
31610 08 Jun 1980 @ 1200 --- research-mab June 8 1980 - no time noted - Dark Cavern Geyser – eruptions appear to be more powerful and frequent 204ºF ie
5078 01 Jun 1980 @ 1800 --- research-mab 06/01/1980 Dark Cavern was quite forceful.
31945 20 Sep 1979 @ 1800 --- research-mab Thursday Sept 20 1979 - Disturbance check after 1730- Dark Cavern Geyser - saw only one weak eruption of clear water 18:10. Temperatures while steaming – 195ºF
31927 11 Sep 1979 @ 1200 --- research-mab Sept 11 1979 -no time noted - Temps taken in Porcelain this AM - Dark Cavern during minor play 198° - steam vent (west vent) 199° minor play occurring every few minutes
32165 18 Aug 1978 @ 1200 --- research-mab 08/18/1978 - no times noted - Blue Geyser -Fireball -Africa – Dark Cavern- Splutter Pot – Constant – Bear Den – Big Whirligig – Moxie {<-- bracket} All active this afternoon.
32081 15 Apr 1978 @ 1200 --- research-mab 04/15/1978 - no time noted - Dark Cavern was having powerful eruptions today. Sprays were forcefully slamming against the side of the vent, causing bursts some 10 feet high.
5094 02 Apr 1978 @ 1800 --- research-mab 04/02/1978 Dark Cavern is having gentle eruptions about every 5 min.
32033 07 Mar 1978 @ 1200 --- research-mab Tuesday March 7 1978 - no time noted - Geysers observed in eruption today were: Bear Den, Feisty, L. Whirligig, Dark Cavern (minor) ie no discharge, Constant, Growler (C.S.) Splutterpot, Fireball, Unnamed, north end of Porcelain Terrace, Africa, Steamboat (minor) Blue, Echinus
5108 28 Jun 1977 @ 1200 --- research-mab 06/28/1977 - no times - 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.
32266 14 Jun 1977 @ 1200 --- research-mab 06/14/1977 - no time noted - Dark Cavern – erupts up to 12’ high 190º
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.
32556 08 Sep 1976 @ 1900 --- research-mab 09/08/1976 - no time noted - {"last night" in 9-9 log} 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.
32510 31 Aug 1976 @ 1200 --- research-mab 08/31/1976 - no time noted - We are for sure in the grip of an end-of-the-season change! Porc Basin has gone bananas! Across the board from Colloidal, a boiling patch has begun in the gray pool located in the runnof channel from Colloidal. Many of the pools located near Dark Cavern have a brown scum on their muddy surfaces.
32488 18 Aug 1976 @ 1200 --- research-mab 08/18/1976 - no time noted - Dark Cavern again appears to be making more noise.
32430 20 Jul 1976 @ 1200 --- research-mab July 20 1976 - no time noted - Porcelain Basin observations in pm: Dark Cavern continues to show more power than earlier this summer.
32410 12 Jul 1976 @ 1200 --- research-mab July 12 1976 - no time noted - Dark Cavern Geyser has been extremely active. Some water has been ejected to a height of 12’.
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.
32337 17 May 1976 @ 1200 --- research-mab May 17 1976 - no times noted - saw the following geysers in action:African (continuous), Constant, Big whirligig, Valentine, Dark Cavern, Vixen, Corporal, (Fan?)
5612 06 Aug 1975 @ 1800 --- research-mab 08/06/1975 Dark Cavern seems to have almost constant action lately.
5601 15 Jul 1975 @ 1200 --- research-mab 07/15/1975 - no times noted - 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.
32795 03 Sep 1973 @ 1800 --- research-mab 09/03/1973 ~ 6:00 p.m. Porcelain Basin conditions: Dark Cavern steam (no recent mud eruptions)
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
32965 02 Oct 1971 @ 1200 --- research-mab 10/02/1971 - no time noted - Some more dying plans & steam observed in old amphitheater south of Dark Cavern Geyser.
33345 31 Jul 1971 @ 1200 --- research-mab 1971 – playing as last year- no change = July 31 - no time - water 89C several small “eruptions” will take place before the major eruption. Not playing as often or not all plays are minor eruptions (192F)
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.
33344 14 Jul 1970 @ 1200 --- research-mab July 14 1970 - no time - The center is losing the dark color, the color is more of a light brown and cream color. Picture taken. Aug 18 air 65 F - water 200F
33343 30 Jun 1970 @ 1200 --- research-mab June 1970 - no time- playing about every 5 to 10 minutes as last year. [NOTE no date in Thermal Record – EOM]
33308 18 Aug 1969 @ 1200 --- research-mab 1969 - no time noted - playing about every ____ minutes. - Aug 18. Will have a little activity every two minutes, but no water overflow. Erupts with overflow about every 23 minutes. 188ºF The water is more opal in color than last year.
33307 13 Jun 1967 @ 1535 --- research-mab 6/13/1967 - no time noted inferred time - The geyser has a minor eruption every minute or two. The major eruptions come every several hours. During a major eruption the west vent is cooled down with water from the east vent and water will also leave the basin and run to the west. Two new steam vents have broken out about 5 feet southwest of the geyser since last year, also a new spring nine feet west. The geyser is not creating the “sink sucking” noise that it did last year. The east vent will put out water to the extent that the steam is stopped in the west vent. 190ºF with a pH of 5 at 180ºF
33305 04 Jun 1967 @ 1200 --- research-mab June 4 1967 - no time - Playing 2 to 5 ft.
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.