Last Known Eruption
3h 16m ago
Predicted Next Eruption
Today at 2300 ± 60 minutes

Latest Eruptions

Eruption DurationInterval
18 Aug 2025 @ 0530 A maj16h 41m
17 Aug 2025 @ 1249 wc min3m 1d 2h 35m
16 Aug 2025 @ 1014 ns maj22h 30m
15 Aug 2025 @ 1144 maj20h 11m
14 Aug 2025 @ 1533 wc maj7h 0m
14 Aug 2025 @ 0833 min18h 26m
13 Aug 2025 @ 1407 maj8h 13m
13 Aug 2025 @ 0554 min18h 5m
12 Aug 2025 @ 1149 maj4h 22m
12 Aug 2025 @ 0727 min2m 16h 43m
11 Aug 2025 @ 1444 maj1d 17h 26m
09 Aug 2025 @ 2118 wc min16h 18m
09 Aug 2025 @ 0500 maj16h 45m
08 Aug 2025 @ 1215 maj18h 37m
07 Aug 2025 @ 1738 ie maj1d 4h 34m
06 Aug 2025 @ 1304 ie wc maj7h 44m
06 Aug 2025 @ 0520 ie wc min19h 26m
05 Aug 2025 @ 0954 ie wc maj16h 22m
04 Aug 2025 @ 1732 min1d 11h 47m
03 Aug 2025 @ 0545 ns wc maj21h 33m
02 Aug 2025 @ 0812 min17h 35m
01 Aug 2025 @ 1437 maj18h 32m
31 Jul 2025 @ 2005 ns maj38+6h 8m
31 Jul 2025 @ 1357 wc min4m 17h 55m
30 Jul 2025 @ 2002 ns wc maj11h 46m
30 Jul 2025 @ 081619h 40m
29 Jul 2025 @ 1236 ie maj1d 2h 52m
28 Jul 2025 @ 0944 ns min3h 33m
28 Jul 2025 @ 0611 ie wc min19h 15m
27 Jul 2025 @ 1056 ie maj18h 28m
26 Jul 2025 @ 1628 min1d 9h 28m
25 Jul 2025 @ 0700 ie maj18h 17m
24 Jul 2025 @ 1243 maj1d 4h 53m
23 Jul 2025 @ 0750 ie wc maj22h 26m
22 Jul 2025 @ 0924 maj16h 47m
21 Jul 2025 @ 1637 maj1d 9h 4m
20 Jul 2025 @ 0733 wc maj18h 22m
19 Jul 2025 @ 1311 maj1d 5h 0m
18 Jul 2025 @ 0811 maj1d 7m
17 Jul 2025 @ 0804 min18h 9m
16 Jul 2025 @ 1355 ie wc maj1d 6h 30m
15 Jul 2025 @ 0725 maj18h 17m
14 Jul 2025 @ 1308 wc maj1d 1h 3m
13 Jul 2025 @ 1205 maj16h 58m
12 Jul 2025 @ 1907 maj16h 40m
12 Jul 2025 @ 0227 maj18h 21m
11 Jul 2025 @ 0806 ie wc maj1d 22h 32m
09 Jul 2025 @ 0934 maj16h 49m
08 Jul 2025 @ 1645 maj16h 31m
08 Jul 2025 @ 0014 maj~18m 17h 9m
07 Jul 2025 @ 0705 wc maj20h 35m
06 Jul 2025 @ 1030 wc maj4h 52m
06 Jul 2025 @ 0538 min17h 35m
05 Jul 2025 @ 1203 maj1d 58m
04 Jul 2025 @ 1105 maj17h 28m
03 Jul 2025 @ 1737 maj16h 27m
03 Jul 2025 @ 0110 maj17h 36m
02 Jul 2025 @ 0734 wc maj3h 33m
02 Jul 2025 @ 0401 min~5m 15h 56m
01 Jul 2025 @ 1205 maj17h 39m
30 Jun 2025 @ 1826 ie wc maj20h 22m
29 Jun 2025 @ 2204 wc maj1d 16h 47m
28 Jun 2025 @ 0517 wc maj8h 59m
27 Jun 2025 @ 20182d 10h 31m
25 Jun 2025 @ 0947 wc min4h 39m
25 Jun 2025 @ 0508 min16h 52m
24 Jun 2025 @ 1216 maj17h 45m
23 Jun 2025 @ 1831 ns wc maj1d 9h 38m
22 Jun 2025 @ 0853 maj16h 30m
21 Jun 2025 @ 1623 maj1d 9h 45m
20 Jun 2025 @ 0638 ie wc maj17h 59m
19 Jun 2025 @ 1239 maj6h 29m
19 Jun 2025 @ 0610 wc min18h 54m
18 Jun 2025 @ 1116 wc maj15h 1m
17 Jun 2025 @ 2015 wc min3m 1d 12h 42m
16 Jun 2025 @ 0733 wc maj16h 47m
15 Jun 2025 @ 1446 maj11h 4m
15 Jun 2025 @ 0342 ie wc min5h 17m
14 Jun 2025 @ 2225 wc min17h 47m
14 Jun 2025 @ 0438 ie wc maj5h 33m
13 Jun 2025 @ 2305 ? wc min17h 35m
13 Jun 2025 @ 0530 ns wc maj10h 20m
12 Jun 2025 @ 1910 wc min18h 26m
12 Jun 2025 @ 0044 wc maj11h 47m
11 Jun 2025 @ 1257 min~3m 15h 53m
10 Jun 2025 @ 2104 wc maj16h 23m
10 Jun 2025 @ 0441 wc maj16h 53m
09 Jun 2025 @ 1148 maj16h 3m
08 Jun 2025 @ 1945 wc maj17h 32m
08 Jun 2025 @ 0213 wc maj1d 21h 39m
06 Jun 2025 @ 0434 ns wc maj13h 23m
05 Jun 2025 @ 1511 min4m 25s 1d 7h 45m
04 Jun 2025 @ 0726 ns wc maj18h 4m
03 Jun 2025 @ 1322 ie wc maj6h 12m
03 Jun 2025 @ 0710 wc min16h 23m
02 Jun 2025 @ 1447 wc maj19h 23m
01 Jun 2025 @ 1924 maj14h 5m
01 Jun 2025 @ 0519 min16h 9m
31 May 2025 @ 1310 maj17h 28m
30 May 2025 @ 1942 ie wc maj12h 50m

Interval Statistics

Interval Count100
Min3h 33m
Max2d 10h 31m
Mean19h 11m
Median17h 35m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
41093 15 Aug 2025 @ 1057 --- underarockphoto Castle has been having frequent heavy splashes for the last hour or two through its window. Surges that, normally, should start an eruption. In many ways it looks like post minor behavior. This note was placed when it was 30min outside the back end of the window.
40942 10 Aug 2025 @ 0831 --- EmilyW Quiet, had an overnight major eruption
38310 25 Feb 2025 @ 0002 --- K.Cooper recently had a major
37656 20 Oct 2024 @ 0915 --- aferrara heavy voluminous splashing, no eruption since minor yesterday morning
37572 14 Oct 2024 @ 0855 --- aferrara hardly steaming, voluminously splashing, probably a minor over night.
37519 11 Oct 2024 @ 0552 --- K.Cooper lightly huffing had a major overnight
37405 05 Oct 2024 @ 0755 --- Graham Major overnight
37239 29 Sep 2024 @ 0915 --- User34 Heavy sloshing, did not major overnight
36576 27 Aug 2024 @ 1932 --- MikeG (wc) Either had some large splashes or another minor eruption, I'm not sure which.
36376 12 Aug 2024 @ 0651 12 Aug 2024 @ 0705 JimS Boardwalk soaked, Castle steaming quietly. Had a major eruption overnight
36332 09 Aug 2024 @ 0718 --- JimS Sloshing. Had a minor eruption overnight
36308 07 Aug 2024 @ 0621 --- JimS Sloshing. Had a minor eruption
36306 06 Aug 2024 @ 1903 --- Dan A Had a minor sometime earlier
36239 03 Aug 2024 @ 0614 --- JimS steaming quietly, had a major eruption overnight
36192 01 Aug 2024 @ 0623 --- JimS Sloshing. was a minor
36186 31 Jul 2024 @ 0626 --- JimS Sloshing. Had a minor eruption overnight
36145 28 Jul 2024 @ 0620 --- JimS Steaming quietly. Had a major eruption overnight
36012 21 Jul 2024 @ 0600 --- JimS Sloshing. Still no major
35992 20 Jul 2024 @ 0631 --- JimS Sloshing. Has not yet had a major eruption
35866 13 Jul 2024 @ 0550 --- JimS Steaming quietly. Had a major eruption overnight
35830 11 Jul 2024 @ 0546 --- JimS Steaming quietly. Had a major eruption overnight
35795 09 Jul 2024 @ 0606 --- JimS Steaming quietly. Had a major eruption overnight
35772 08 Jul 2024 @ 0542 --- JimS Sloshing. Had a minor eruption overnight
35753 07 Jul 2024 @ 0609 --- JimS Still sloshing. No major yet
35723 05 Jul 2024 @ 0552 --- JimS Still sloshing. No major yet
35655 01 Jul 2024 @ 0550 --- JimS Steaming quietly. Had a major eruption overnight
35634 30 Jun 2024 @ 0928 --- Polly Castle is in steam phase
35624 30 Jun 2024 @ 0607 --- JimS Still sloshing. Has not yet had a major eruption.
35582 27 Jun 2024 @ 0610 --- JimS Steaming quietly. Had a major eruption overnight
35542 25 Jun 2024 @ 0610 --- JimS Has been steaming quietly. Had a major eruption overnight.
35133 12 Jun 2024 @ 0604 --- JimS Still sloshing. Has not had a major eruption yet.
35020 09 Jun 2024 @ 0259 --- Mikemcc post major steam phase
34951 07 Jun 2024 @ 0550 --- JimS Quiet. Had a major eruption overnight
34745 29 May 2024 @ 0804 --- Stephen_Gemar Sloshing. Likely had a minor overnight.
34484 09 May 2024 @ 0610 --- CraigC Castle looks to be in post-eruptive steam phase
34386 30 Apr 2024 @ 1803 --- MikeG ie, looks like it might quit at any moment. (But apparently it didn't)
34108 11 Mar 2024 @ 1728 --- K.Cooper Splashing, water is already back.
34040 16 Feb 2024 @ 0704 --- JarnoO (wc) Looked like it was in steam and would fit with NPS' 2345 prediction. Also implies a minor happened overnight. 0704 is the first time it was brought in view after the cam was parked on its overnight spot with Castle off-screen (sigh... with Castle in view there's still plenty of room for Beehive to be in frame).
33736 03 Jan 2024 @ 1100 --- mhvogel Castle had a major overnight
32936 16 Dec 2023 @ 0940 --- Pholli minor eruption this morning. steaming quietly with active bursts
28527 28 Sep 2023 @ 0830 --- User34 Huffing steam, one steamy splash, appears to have majored overnight
28440 24 Sep 2023 @ 1230 --- MikeG (wc) Looks like it had a minor overnight and is in sloppy phase.
28416 22 Sep 2023 @ 1640 --- jonp (WC) Appears to be in post-minor splashing mode
28229 12 Sep 2023 @ 0730 --- Ben VL Has had a major since last night's minor.
27513 11 Aug 2023 @ 0558 --- JimS Steaming quietly, had a major eruption overnight after the minor
27471 09 Aug 2023 @ 0609 --- JimS Steaming quietly. Had a major eruption overnight
27206 25 Jul 2023 @ 0600 --- JimS Sloshing. Boardwalk wet. Had a minor eruption
27079 16 Jul 2023 @ 0544 --- JimS Still sloshing. No major yet
27015 12 Jul 2023 @ 0530 --- JimS Steaming quietly. Had a major eruption overnight.
26954 09 Jul 2023 @ 0543 --- JimS Still sloshing. No major yet.
26781 02 Jul 2023 @ 0535 --- JimS Quietly steaming. Last eruption was a major
26757 01 Jul 2023 @ 0530 --- JimS Steaming quietly. Had a major eruption overnight
26688 27 Jun 2023 @ 0529 --- JimS Still trying to recover from overnight minor
26674 26 Jun 2023 @ 0538 --- JimS Must have had a minor overnight before the 0515 major
26389 17 Jun 2023 @ 0534 --- JimS Steaming quietly. Had a major eruption overnight
26350 16 Jun 2023 @ 0538 --- JimS Steaming quietly. Had a major eruption overnight.
26326 15 Jun 2023 @ 0538 --- JimS Sloshing. Had a minor eruption overnight.
26251 12 Jun 2023 @ 0530 --- JimS Quiet. Overnight eruption was a major.
26204 10 Jun 2023 @ 0555 --- JimS Steaming quietly. Overnight eruption was a major
25406 14 May 2023 @ 0610 --- User34 Still post-minor
25242 25 Apr 2023 @ 0839 --- Colin_W Looking like the last eruption was a minor.
25068 03 Mar 2023 @ 1426 --- Colin_W looks like it did a minor
25067 03 Mar 2023 @ 1044 --- ltgangi castle water could be seen just above tree line several times and then it died.down.
25031 23 Feb 2023 @ 0432 --- JarnoO possible start time of an eruption - frequently obscured by steam from elsewhere (primarily MYR) and darkness didn't help
24432 16 Oct 2022 @ 1800 --- Ben VL Almost no splashing seen in quite a while. I think either the 0316E was actually a major, or it has had one since.
24391 15 Oct 2022 @ 1136 --- Ben VL Castle back on after 5m of quiet. Done again @ 1139. See the 1127 entry for details.
23471 29 Aug 2022 @ 0615 --- JimS Sloshing. Had a minor eruption overnight.
23454 28 Aug 2022 @ 0618 --- JimS Sloshing. Had a minor eruption overnight.
23406 26 Aug 2022 @ 0615 --- JimS Steaming quietly. Had a major eruption overnight.
23380 24 Aug 2022 @ 0611 --- JimS Sloshing. Last eruption was a minor.
23342 22 Aug 2022 @ 0616 --- JimS Sloshing. Last eruption was a minor.
23308 21 Aug 2022 @ 0615 --- JimS Steaming quietly. Apparently had a major eruption overnight.
23222 17 Aug 2022 @ 0605 --- JimS Steaming quietly. Appears to have had a major eruption.
23110 09 Aug 2022 @ 0703 --- JimS Has been sloshing the last hour. Had a minor eruption overnight.
23095 08 Aug 2022 @ 0556 --- JimS Sloshing. Still trying to recover from minors.
23085 07 Aug 2022 @ 0621 --- JimS Has been steaming quietly. Had a major eruption overnight.
23067 06 Aug 2022 @ 0559 --- JimS Quiet. Had a major eruption overnight.
23022 04 Aug 2022 @ 0607 --- JimS Sloshing. Had a minor eruption overnight.
22970 02 Aug 2022 @ 0528 --- JimS Steaming gently, boardwalk soaked. Had a major eruption overnight.
22901 28 Jul 2022 @ 0540 --- JimS Steaming quietly, boardwalk soaked. Had a major eruption.
22872 27 Jul 2022 @ 0545 --- JimS Still sloshing. Has not yet had a major eruption.
22823 24 Jul 2022 @ 0543 --- JimS Splashing heavily. Had a minor eruption overnight.
22798 23 Jul 2022 @ 0534 --- JimS Splashing heavily. Trying to recover from a minor eruption. May have had a second minor overnight
22802 22 Jul 2022 @ 1934 --- DinosaursArentReal tourist showed me a video of castle erupting about 5 ft. video was timestamped from 1934-1939
22753 21 Jul 2022 @ 0547 --- JimS Quiet. Boardwalk soaked. Had a major eruption overnight.
22584 15 Jul 2022 @ 0535 --- JimS Was a major eruption.
22372 07 Jul 2022 @ 0524 --- JimS Steaming quietly. Had a major eruption overnight.
22348 06 Jul 2022 @ 0551 --- JimS Still trying to recover from a minor eruption. Splashing heavily.
22334 05 Jul 2022 @ 0514 --- JimS Quiet steaming. Had a major eruption overnight.
22278 02 Jul 2022 @ 0535 --- JimS Splashing frequently. Had a minor eruption overnight.
22254 01 Jul 2022 @ 0700 --- User34 Large heavy splashes, based on current interval it appears to have minored overnight
22194 29 Jun 2022 @ 0656 --- JimS Castle has been quiet indicating that its overnight eruption was a major
22136 26 Jun 2022 @ 1428 --- DaveM Major erption
21990 16 Jun 2022 @ 0630 --- RMichaels Castle is lightly billowing steam. It probably had a major sometime overnight.
21912 11 Jun 2022 @ 0800 --- Colin_W splashing on cone.
21150 02 May 2022 @ 0915 --- aferrara Heavy, tall splashing.
21134 30 Apr 2022 @ 1300 30 Apr 2022 @ 1630 User34 Splashing heavily
21077 25 Apr 2022 @ 0605 --- RMichaels Quiet. Castle appears to have had a major overnight.
20943 05 Apr 2022 @ 1326 --- Kevin L Castle was not erupting when I switched to Lion ie at 1238. I did a quick check before I switched to OF and Castle looked ie.
20764 29 Jan 2022 @ 0830 --- aferrara Castle is quietly steaming with rare, short splashes. No eruptions on the logger since 1447 yesterday.
EntrySourceLinkComment
23 May 2017 @ 1746 JSJ https://www.youtube.com/watch?v=Xhs0ZWQEJ04 Half-minute video showing Castle Geyser's 5:46 PM-onward eruption on 23 May 2017.
10 Aug 2018 @ 1427 JSJ https://www.flickr.com/photos/jsjgeology/46465868542 Photo (1 of 3) of Castle Geyser's 2:27 PM-onward eruption on 10 August 2018, as seen from boardwalk near Liberty Pool.
28 Jan 2017 @ 1039 JSJ https://www.youtube.com/watch?v=eSORnt-mHN0 Video of Castle Geyser erupting (water phase) on 28 January 2017.
11 Aug 2016 @ 1358 JSJ https://www.flickr.com/photos/jsjgeology/30476239182 Thermal image (1 of 4) of Castle Geyser's 1:58 PM-onward eruption on 11 August 2016.
11 Aug 2016 @ 1358 JSJ https://www.flickr.com/photos/jsjgeology/29959320393 Photo (1 of 7) of Castle Geyser's 1:58 PM-onward eruption on 11 August 2016.
03 Jun 2016 @ 1748 JSJ https://www.flickr.com/photos/jsjgeology/29096074105 Photo (1 of 3) of Castle Geyser's 5:48 PM-onward eruption on 3 June 2016.
03 Jul 2013 @ 0711 JSJ https://www.youtube.com/watch?v=dlT_ulj6fmI Video by Micah Kipple of the 3 July 2013 morning major eruption (steam phase) of Castle Geyser.
03 Jul 2013 @ 0711 JSJ https://www.youtube.com/watch?v=UVClJ3jb52M Video by Micah Kipple of the 3 July 2013 morning major eruption (water phase) of Castle Geyser.
15 Aug 2015 @ 0957 JSJ https://www.youtube.com/watch?v=fP59M_A8la8#t=6m57s See clips # 18-31 (time stamp - 6:57) of this video compilation.
14 Aug 2015 @ 1530 JSJ https://www.youtube.com/watch?v=fP59M_A8la8#t=4m09s See clips # 11-17 (time stamps - 4:09 to 6:57) of this video compilation.
09 Aug 2015 @ 1544 JSJ https://www.youtube.com/watch?v=fP59M_A8la8 See clips # 6-10 of this video compilation.
16 Aug 2014 @ 1234 JSJ https://www.youtube.com/watch?v=fP59M_A8la8 See clips # 3-5 of this video compilation.
06 Jul 2015 @ 1256 JSJ https://www.youtube.com/watch?v=fP59M_A8la8 See clips # 1-2 of this video compilation.
28 Sep 2015 @ 0542 td http://i61.tinypic.com/2hdwbqf.jpg Castle 5:47
08 Sep 2014 @ 1201 Micah Kipple https://www.flickr.com/photos/sgplewka/15582865600 flickr
24 Sep 2014 @ 1338 Micah Kipple https://www.flickr.com/photos/126760153@N03/15642309900 flickr
17 Oct 2014 @ 1224 Micah Kipple https://www.flickr.com/photos/57621754@N08/15785065928 flickr
28 Sep 2014 @ 1458 Micah Kipple https://www.flickr.com/photos/castle_bravo/15661819608 flickr
26 Sep 2012 @ 1234 Micah Kipple https://www.flickr.com/photos/npsaficionado/15830592629 flickr
29 Aug 2011 @ 1444 Micah Kipple https://www.flickr.com/photos/128570456@N08/15922246028 flickr
BaselineDistance (ft)Description
Bike Path 200On the side of the bike path south of the geyser.