Last Known Eruption
9y 355d 4h 19m ago

Latest Eruptions

Eruption DurationInterval
07 Jul 2014 @ 000012y 282d 0m
01 Oct 2001 @ 0000 A27y 54d 0m
15 Aug 1974 @ 000044d 0m
02 Jul 1974 @ 000014d 0m
18 Jun 1974 @ 000010d 16h 0m
07 Jun 1974 @ 0800 A2y 246d 8h 0m
05 Oct 1971 @ 0000

Interval Statistics

Interval Count6
Min10d 16h 0m
Max27y 54d 0m
Mean7y 47d 16h 0m
Median1y 145d 4h 0m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
35427 21 Jun 2024 @ 1547 --- nails Light steam and quiet grumbling
35087 10 Jun 2024 @ 1244 --- SantaFe108 Deep grumbling, steaming.
29032 22 Oct 2023 @ 0848 --- SantaFe108 Gently forcing steam. Root Pool is full, boiling towards the trail. Also boiling in the middle pool and on the rim towards Arch.
28930 20 Oct 2023 @ 1615 --- MAB steamy - pool #1 below it {the gray one} had a boil bringing up dark material = ROOT POOL not as high as reported 2 weeks ago but closer to the high water mark - all pools connected
27339 30 Jul 2023 @ 0843 --- ypcaribou Root Pool quite full (divide between pools fully covered). A light, milky, minty jade green.
27298 28 Jul 2023 @ 2043 --- SantaFe108 Grumbling at depth. Larger two of the three pools to the west are connected. Smallest is bubbling with muddy grey water.
27172 23 Jul 2023 @ 1422 --- mhreed Light, rhythmic huffing.
26944 08 Jul 2023 @ 1918 --- nails Softly grumbling
26823 04 Jul 2023 @ 0850 --- MAB audible grumbling with tiny airborne droplets
24576 30 Oct 2022 @ 1638 --- ypcaribou Huffing deep down in vent. Steam uphill as well. 3 pools area to right is quite flooded toward the far end.
23957 20 Sep 2022 @ 1610 --- ypcaribou Gently steaming with a deep, glutteral rumble. Bit of steam coming out uphill. Three pools to right are: Small is murky tan. Middle is emerald green with scum on surface, water is clear on top. Lg is murky light brownish muddy green.
21008 18 Apr 2022 @ 1725 --- MAB steamy w a dull growl- all pools west of base connected
17740 12 Jun 2021 @ 1623 --- MAB Noisy forced steam - the different colored pools below it on the flats are barely connected
12014 28 Jun 2019 @ 0745 28 Jun 2019 @ 1045 ypcaribou Water in springs below and to the left of Arch Steam Vent about 1-2 feet low.
11028 20 Apr 2019 @ 1031 --- MAB Noisy forced steam
9661 10 Aug 2018 @ 1331 --- MAB Pools below and west are 3 different colors - might suggest different water sources. 1st (closest to Arch) is grayish white, 2nd green, 3rd is taupe.
3998 22 Apr 2017 @ 2020 --- Micah Kipple Heavy wash and debris downslope. Sinter blocks and stones lodged on uphill side of trees and logs. Looks wet but that could be snow melt.
1101 07 Jul 2014 @ 0000 07 Jul 2014 @ 2359 MAB Norris log - Arch Steam Vent showing evidence of eruption- runoff channel and fresh debris in the path
4356 02 Oct 2001 @ 0800 02 Oct 2001 @ 1800 research-mab 10/2/2001 A visitor reported a lot of mud around Arch Steam Vent today. I left the desk briefly to check it out. John Tebby & I walked down and found trees covered in mud, huge mud flows around the boardwalk and a big sink hole in the inside of the boardwalk (NW of the vent). There was a light spatter of mud on the boardwalks as far away as 25 feet. Last recorded eruption {obscured in my captures of the log -will probably find it as I work back in time MAB}
4749 30 Sep 2001 @ 1800 --- research-mab 09/30/2001 ARCH STEAM VENT: Erupted w/ sprays of mud & mudflows & opened up a sink hole. Time unknown.
29952 07 Jul 1998 @ 1200 --- research-mab 7/7/1998 - no time noted - Arch Steam Vent – gently steaming, soft boiling sound
10891 25 Apr 1994 @ 1200 --- research-mab 4/25/1994 {generic day time} A little water was seen from Arch Steam Vent
30358 13 Jul 1992 @ 1200 --- research-mab 7/13/1992 - no time noted - Root Pool -near Arch Steam Vent- has dropped it water level about 2 ft!!
30497 16 May 1991 @ 1200 --- research-mab 5/16/1991 - no time noted - Arch Steam Vent – footprints up the slope, already steaming gently; pool to right at base of hill is blue
33429 06 Oct 1986 @ 1200 --- research-mab October 6, 1986 - no time noted - *ROOT POOL. If it is the normally muddy feature just past (East of) Arch Steam Vent, is almost a foot down from normal levels. Quite a bit of cave-in around the rim of the big pool, maybe not new.
31229 20 Feb 1982 @ 1200 --- research-mab February 20 1982 - no time noted - Arch Steam Vent 203° gently steaming
31534 30 Aug 1981 @ 1200 --- research-mab Sunday August 30 1981 - no time noted - Arch Steam Vent 203° moderate steaming
31471 03 Aug 1981 @ 1200 --- research-mab August 3 1981 - no time noted - Arch Steam Vent – 200º gently puffing
31419 06 Jun 1981 @ 1200 --- research-mab Saturday June 6 1981 - no time noted - Arch Steam Vent – Steaming lustily, water heard boiling deep within. 204°F
31761 15 Sep 1980 @ 1200 --- research-mab Monday September 15, 1980 - no time noted - {disturbance onset -} Arch Steam Vent – No apparent change 202ºF
31962 21 Sep 1979 @ 1200 --- research-mab Friday September 21 1979 - no time noted - More end of summer changes! Arch Steam Vent – unchanged – 200ºF
31845 21 Jun 1979 @ 1200 --- research-mab June 21 1979 Thursday - no time noted - Arch Steam Vent – 201ºF A Robin is nesting in the dead lodgepole below – Mrs. Decker?
32094 02 Jun 1978 @ 1200 --- research-mab 06/02/1978 - no time noted - Arch Steam Vent - 202° F ; blue pool 25 ft to the north 109°
32406 10 Jul 1976 @ 1200 --- research-mab July 10 1976 - no time noted - Lake between Arch Steam Vent and Dishwater Spring is drying up.
5719 15 Aug 1974 @ 1800 --- research-mab 08/15/1974 Arch Steam Vent runoff damp – sign & log retrieved from trees nearby.
5709 18 Jun 1974 @ 1120 --- research-mab 06/18/1974 1120 Marker at Arch Steam Vent washed out, replaced.
5706 07 Jun 1974 @ 1800 --- research-mab 06/07/1974 1655 Visited Arch Steam Vent- definite evidence of eruption w/ hot water in runoff channel. Placed pine-needle marker in runoff channel. {during day - no time noted}
32782 02 Sep 1973 @ 1700 --- research-mab 09/02/1973 - no specific time noted - Back Basin 5pm - Spring W of Arch Steam Vent very low water found in only 3 of the deepest vents.
32897 16 May 1972 @ 1200 --- research-mab 05/16/1972 - no time noted - Arch Steam Vent – wish I could have seen it blow 200º =Pool between Arch Steam Vent and Root pool - 190º
10892 14 May 1972 @ 1000 --- research-mab 5/14/1972 {generic time} Arch Steam Vent {1st observations of the season noting destruction from early Oct 1971 eruption~ 1972 Annual report states it was September {disturbance} activity~~~ included here as some readers of the log may assume a May 1972 eruption.} 5-14-72 Lognote: had one heck of an eruption The erosion in this area is impressive – a new hole opened up to the north and is filled with green water. The trail no longer branches back to the feature
10865 05 Oct 1971 @ 0000 --- research-mab {Seen and photographed Oct 6. eruption presumed night of Oct 5} There was no warning at all to the vent change other than a temperature rise of 1°F on September 12th. When it erupted, the vent was enlarged, its shape changed markedly, muddy water coated the trees clear to the top to a distance of over 80 feet from the vent, the log sign identifying Arch Steam Vent was rolled 30 feet down the slope; in addition mud, pine needles, small logs, and the other debris were washed over the boardwalk below the vent, a gully about a foot in depth was eroded into the hillside, and a small pool to the west-northwest served as a catchment basin for part of the runoff but its level dropped around 2 feet from normal.
33147 21 Jul 1971 @ 1200 --- research-mab 1971- July 21 - no time - steam 93C Not too fast or much noise (189F)
33149 29 Jun 1969 @ 1200 --- research-mab 1969- June 29 – - no time - no change – trees dead on north side of vent, killed last year. 200°F
33150 02 Jun 1968 @ 1200 --- research-mab June 2 1968 - no time - The vent blew up some time this spring. The arch is no longer intact and the trees to the north are dead and covered with gray clay. Clay has also run down the hill on to the trail.
10864 02 Jun 1968 @ 0000 --- research-mab Arch Steam Vent June 2 1968 The vent blew up some time this spring. The arch is no longer intact and the trees to the north are dead and covered with gray clay. Clay has also run down the hill on to the trail.
33001 11 Sep 1967 @ 1200 --- research-mab 09/11/1967 - no time noted - Root Spring full again – The small pools just past Arch have also refilled. 164º
No attachments for this geyser.
Baseline does not exist.