Last Known Eruption
30y 98d 19h 39m ago

Latest Eruptions

Eruption DurationInterval
18 Jul 1991 @ 2100 ns maj~4 water ~40 heavy steam1y 17d 9h 0m
01 Jul 1990 @ 1200 A

Interval Statistics

Interval Count1
Min1y 17d 9h 0m
Max1y 17d 9h 0m
Mean1y 17d 9h 0m
Median1y 17d 9h 0m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
18300 06 Jul 2021 @ 1505 --- User34 Overflowing and bubbling slightly
17427 04 Jun 2021 @ 0946 --- Stephen_Gemar Pool appears to have dropped from my earlier observation. Infrequent light bubbling observed at this time.
17426 04 Jun 2021 @ 0916 --- Stephen_Gemar Pool is overflowing, with light bubbling. Overflow is still light, but runoff has flown far down the front side of Whistle, to within fifteen feet of the trees by the road.
17404 03 Jun 2021 @ 1015 --- Stephen_Gemar Whistle’s runoff is much dryer compared to last observation. The pool appears to be below the level it was at a couple of days ago. The top-middle portion of its runoff is still white-orange.
17316 31 May 2021 @ 1905 --- Stephen_Gemar Whistle is hot enough to have turned part of its runoff channel white-orange. Some occasional light bubbling seen. Overflow still appears to be light, but enough to overflow its main runoff channel.
14655 17 Jun 2020 @ 1110 --- Janet Jones Overflowing and bubbles making 1” splashes.
762 18 Jul 1991 @ 0000 18 Jul 1991 @ 2359 geysergaze Observed NS from Old Faithful Overpass. water phase lasted over four minutes, which is very long historically. Most water phases last about a minute.
19758 12 May 1991 @ 0000 24 May 1991 @ 0000 mhreed From the July–August 1991 Sput (Vol. 5 No. 4): "...it was realized by [Rocco] Paperiello and [Mike] Keller that deep runoff channels marked Whistle's cone, showing that an eruption must have occurred between May 12 and 24." In a post to the geyser listserv dated 1997/01/12, Paperiello writes: "As to the May eruption, I was keeping an eye on Whistle in 1991, and have the eruption in May down to between the 12th and the 18th, assuming that it takes 2 1/2 days to again reach overflow after an eruption."
Baseline does not exist.