| Note ID | Start Time (US/Mountain) | End Time (US/Mountain) | Entrant | Note |
| 37901 |
31 Oct 2024 @ 1046 |
--- |
MAB |
light steam - also will note the pools on the flat below DC in vicinity of Lewis Mudpot water level ~2in below ground level |
| 37768 |
25 Oct 2024 @ 1643 |
--- |
MAB |
quiet steam not forced |
| 37352 |
03 Oct 2024 @ 1054 |
--- |
SantaFe108 |
Steaming decently, air temp ~40° F. |
| 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. |