Last Known Eruption
26y 32d 17h 0m ago

Latest Eruptions

Eruption DurationInterval
27 Aug 1995 @ 1020 min7m 333d 23h 5m
27 Sep 1994 @ 1115 min9d 2h 55m
18 Sep 1994 @ 0820 ie min12m 9d 21h 35m
08 Sep 1994 @ 1045 min106d 15h 45m
24 May 1994 @ 1900 min

Interval Statistics

Interval Count4
Min9d 2h 55m
Max333d 23h 5m
Mean114d 21h 50m
Median58d 6h 40m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
19228 01 Sep 2021 @ 1627 --- MAB trickle overflow
18832 04 Aug 2021 @ 0855 --- MAB light boil but virtually no overflow
18334 09 Jul 2021 @ 0845 --- MAB moderate overflow - Branch Sp in a Very vigorous boil via sound and waves - too steamy to see a thing
18275 05 Jul 2021 @ 1531 --- cb pool is about 2" below high water mark. Roiling boil 2 - 4" on either side of the rock formation
18262 03 Jul 2021 @ 0849 --- MAB moderate overflow - Branch Sp was quiet
18150 28 Jun 2021 @ 1946 --- MAB very light overflow
18156 28 Jun 2021 @ 0834 --- MAB moderate overflow
18091 25 Jun 2021 @ 1139 --- MAB moderate overflow
17928 19 Jun 2021 @ 0900 --- MAB strong overflow
17802 15 Jun 2021 @ 1109 --- cb blooping boil 2"-3". in good overflow
17799 14 Jun 2021 @ 0902 --- MAB strong overflow
17462 04 Jun 2021 @ 0924 --- MAB good overflow
17205 27 May 2021 @ 1953 --- MAB fairly strong overflow- small waves on pool
17183 25 May 2021 @ 0907 --- MAB light overflow
17142 19 May 2021 @ 0923 --- MAB light overflow
17121 17 May 2021 @ 2019 --- MAB in overflow
17120 17 May 2021 @ 0928 --- MAB in overflow
17034 09 May 2021 @ 1302 --- cb pool is a murky yellow/ lime green color with a 2" roiling boil over both main vents.
16972 30 Apr 2021 @ 0922 --- MAB light overflow
16890 20 Apr 2021 @ 0942 --- MAB quiet
16349 06 Oct 2020 @ 1322 --- cb light emerald green in color with 3 mildly roiling points on the east side of the rock. Occational roiling activity on the other side of the rock.
16267 26 Sep 2020 @ 1602 --- cb clear, green in color with a weak boil
15554 13 Aug 2020 @ 1118 --- cb Pool is SO clear and beautiful! average boil over the vent at the edge of the big rock.
14924 10 Jul 2020 @ 1155 --- bbev Moderate boil and light runoff from very clear pool.
14602 11 Jun 2020 @ 1749 --- cb pool is a pretty, clear, emerald green color with 2 rolling bubblers that break the surface on the N side of the big rock in the pool.
13386 25 Aug 2019 @ 0633 --- ypcaribou Splashing up to left of long rock in at least 2 spots maybe 6" to a foot. Light overflow on right side of channel.
13383 24 Aug 2019 @ 1944 --- MAB Strongest boil I've seen in a long time - left of the rock. Normal low boil to the right of the rock.
13010 03 Aug 2019 @ 1955 --- Stephen_Gemar Boiling in a couple of spots to the left of the big boulder, and light roiling in 1 spot to the right of the big boulder. A little water trickling into the runoff channel.
12007 28 Jun 2019 @ 1053 --- ypcaribou Water trickling into runoff channel. Roiling in blue water to left of big boulder.
12006 28 Jun 2019 @ 0638 --- ypcaribou No water flowing into runoff channel. Water at left edge of pool about an inch lower than prior observations since May 2018.
11619 07 Jun 2019 @ 0944 --- CrisG Boiling to 6-8" left of the large center rock. Pool gently overflowing. Water is still green but is clearer than "normal".
11383 27 May 2019 @ 0933 --- jkgood In overflow. Spluttering and boiling to 6”
11670 24 May 2019 @ 0915 --- Ben VL Boiling a few inches high in two or three spots (plus some smaller boiling spots) near and along the left side of the rock that sticks out of the middle.
11316 22 May 2019 @ 0657 --- Kyle overflowing, gentle boiling 8-10 inches to left of center rock in crater
11329 21 May 2019 @ 0938 --- Kyle pool calm and quiet. barely overflowing
11332 20 May 2019 @ 0915 --- Kyle quiet pool, very light overflow
9519 07 Aug 2018 @ 1147 --- bbev Water in crater is clearer than I have seen this year, no change in runoff.
19283 05 Jul 2018 @ 1201 --- research-mab 7-5-2018 MONARCH BBEV 1201 See Note under Steamboat Porcelain Basin still very active, but appears drier. Congress pool down 4-6" from yesterday, still boiling vigorously. Emerald Springs and Monarch runoff appears to have increased. Monarch geyser crater has clearer water and much fuller. Corperal boiling, runoff wet. Cistern did not look any different, boiling steadily, just at overflow. Emerald Springs is still cloudy but with noticeably less boiling. https://geysertimes.org/note.php?id=9039
3227 24 Jun 2016 @ 1113 --- David level high. bubbling in larger pool, left side of island. see photo: https://www.flickr.com/photos/ujelang/27505616783/in/dateposted-public/
1577 11 May 2015 @ 1308 --- MAB heavy overflow
4722 23 Jun 1994 @ 1800 --- research-mab June 23 1994 – Monarch having series of eruptions then days of nothing
12653 31 May 1994 @ 0000 31 May 1994 @ 2359 JarnoO active
12652 30 May 1994 @ 0000 30 May 1994 @ 2359 JarnoO active
12651 29 May 1994 @ 0000 29 May 1994 @ 2359 JarnoO active
5687 07 Sep 1975 @ 1800 --- research-mab 09/07/1975 A new spring has opened up in the runoff channel of Emerald due north of Monarch Geyser Crater. All water from Emerald drains down vent.
5655 24 Aug 1975 @ 1800 --- research-mab 08/24/1975 Monarch Geyser – boiling has decreased in vent lying between the 3 large rocks. Is back to normal. Same with front vent.
5644 21 Aug 1975 @ 1800 --- research-mab 08/21/1975 Monarch Geyser – looks almost the same as it did immediately after the June 30th quake. Material of a deep charcoal gray color now covers the pool area, runoff channels. & makes the water in the vents quite cloudy. Great increase in activity in vent lying between the 2 large rocks. Large boiling spot located near edge of pool is perhaps 2’ in diameter & 6” high. Scattered bubbles rising in rest of vent. In “front” vent, (main pool area), boiling has also increased in size of area boiling as well as vigor.
5664 05 Aug 1975 @ 1800 --- research-mab 08/05/1975 Monarch Geyser Crater producing some kind of film on the water.
5647 21 Jun 1975 @ 1530 21 Jun 1975 @ 1630 research-mab 08/21/1975 What’s Going On? Monarch is spouting steam bubbles from its quiet side as much as it does from its active side. Cistern appears to be more violent, and Emerald has gone crazy. (Observed in Walk 6, 3:30 to 4:30)
6525 10 Sep 1971 @ 1800 --- research-mab 09/10/1971 Monarch Geyser Crater – the water is still a yellow-green in color, apparently from the sulphur down below but today has started to become slightly turbid from the boiling activity; it has been increasing in vigor very slowly over the past 3-4 weeks.
7408 21 Jul 1968 @ 1800 --- research-mab 07/21/1968 Monarch – H2O from vents surging 5-6 inches. Temp 199.7F
7329 08 Sep 1967 @ 1800 --- research-mab 09/08/1967 Monarch Geyser Whereas Monarch appeared to be a quiet, almost stagnant, pool early this summer, it is now a very clear green color and boiling vigorously. Two vents boiled continuously on the east side of a rock that extends across the pool dividing it into two large rifts. The vents are 198.8ºF and boil up 3-4 inches. No record was made of Monarch early this summer because it showed very little activity. Correction: Ed Leigh recorded 194º on June 22 and ph5 at 140º
6764 16 Oct 1964 @ 1800 --- research-mab 10/16/1964 Monarch is clear & there is very little agitation at 187º
No attachments for this geyser.
Baseline does not exist.