| Note ID | Start Time (US/Mountain) | End Time (US/Mountain) | Entrant | Note |
| 21008 |
18 Apr 2022 @ 1725 |
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MAB |
steamy w a dull growl- all pools west of base connected |
| 17740 |
12 Jun 2021 @ 1623 |
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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 |
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MAB |
Noisy forced steam |
| 9661 |
10 Aug 2018 @ 1331 |
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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 |
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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 |
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research-mab |
09/30/2001 ARCH STEAM VENT: Erupted w/ sprays of mud & mudflows & opened up a sink hole. Time unknown. |
| 10891 |
25 Apr 1994 @ 1200 |
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research-mab |
4/25/1994 {generic day time}
A little water was seen from Arch Steam Vent |
| 5719 |
15 Aug 1974 @ 1800 |
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research-mab |
08/15/1974 Arch Steam Vent runoff damp – sign & log retrieved from trees nearby. |
| 5716 |
02 Jul 1974 @ 1800 |
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research-mab |
07/02/1974 Arch Steam Vent (Geyser) – has erupted sometime in past 2 days. Marker washed out. |
| 5709 |
18 Jun 1974 @ 1120 |
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research-mab |
06/18/1974 1120 Marker at Arch Steam Vent washed out, replaced. |
| 5706 |
07 Jun 1974 @ 1800 |
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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} |
| 10892 |
14 May 1972 @ 1000 |
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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 |
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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. |
| 10864 |
02 Jun 1968 @ 0000 |
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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. |