Grewingk (1850, translated 2003 by Fritz Jaensch) writes that Krenitsyn reported "two volcanoes active on Unalaska" in 1768. He also writes that there are two fire-belching mountains on Unalaska in 1768-69. Although one of these volcanoes is certainly Makushin, the "other" volcano's name and location are unknown. There is some discrepancy about the duration of this eruption. Grewingk (1850, translated 2003 by Fritz Jaensch) mentions only Krenitsyn's account in 1768 and that Cook in 1778 reported the island inactive. However, McGimsey and Miller (1995), and Miller and others (1998) report the dates of this eruption as from 1768-1779; Powers (1958), Jacob and Hauksson (1983), Simkin and Siebert (1994), and Beget and others (2000) report the dates as 1768-1769. Powers (1958) also specifies that this was an ash eruption; many subsequent compilers state that this was a violent ash eruption, or a major eruption.

Grewingk (1850, translated 2003 by Fritz Jaensch) quotes Sarychev: "On the seventh of June 1790, the Makushin volcano was smoking. But it has not burned for a long time. Only now and then (on Feb. 14, 1792) did it expel smoke." The English translation of Sarychev does mention that he saw Makushin on those dates, but is unclear whether or not he saw smoke from Makushin: "It is higher than all the other mountains of Unalaska, with a summit more level than pointed; that on the southern side of the island has the appearance of being almost flat; all eruptions have long since ceased, and nothing now remains but occasional smoke. Earthquakes are likewise now very rare, which were formerly frequent and so violent as to overturn jurts and pendant rocks. On the summit of this crater the Aleutians collect sulphur and lava; from which the latter they make points for their darts."

Grewingk (1850, translated 2003 by Fritz Jaensch) quotes Sarychev: "On the seventh of June 1790, the Makushin volcano was smoking. But it has not burned for a long time. Only now and then (on Feb. 14, 1792) did it expel smoke." The English translation of Sarychev does mention that he saw Makushin on those dates, but is unclear whether or not he saw smoke from Makushin: "It is higher than all the other mountains of Unalaska, with a summit more level than pointed; that on the southern side of the island has the appearance of being almost flat; all eruptions have long since ceased, and nothing now remains but occasional smoke. Earthquakes are likewise now very rare, which were formerly frequent and so violent as to overturn jurts and pendant rocks. On the summit of this crater the Aleutians collect sulphur and lava; from which the latter they make points for their darts."

Dall (1884) writes that in 1796, disturbances on nearby Bogoslof were accompanied by volcanic activity in the craters of Makushin on Unalaska Island, as well as in craters of volcanoes on Umnak Island.
Sapper (1917) reports underwater explosions off the southeast coast [of Unalaska] in 1795. Perhaps this date is in error and should be in 1796. If so, this report could be talking about Bogoslof, or about some other submarine activity near Unalaska.

Grewingk (1850, translated 2003 by Fritz Jaensch) writes that Langsdorff reported strong earthquakes and fire-eruption of Makushin in 1802.
Langsdorff (1812, translated by Victoria Joan Moessner, 1993) reports that "Unalaska had heavy earthquakes almost every month until 1802, when finally there was an extraordinary earthquake, one never experienced there before, that destroyed several huts. In 1806, they could no longer remember exactly in which month it had happened, so unremarkable is such an exceptional natural event for the inhabitants of that area.
"Since then, the peak of the new island [Bogoslof?] has ceased to burn brightly. The volcano on Unalaska, however, suddenly roared again mightily for the first time in many years. It, as well as the volcano on Unimak and the new island, reciprocally burned and smoked." This report does not state which year the "burning and smoking" occurred in.
Plummer (1898) translates Grewingk as "Makushin active with flames and smoke."
Sapper (1917) is more hesitant about the eruption aspects of this event, and questions the "fire-spewing" notations.

Veniaminov (1840, translated in 1984 by Lydia Black and R. H. Geoghegan) wrote about Makushin: "No one remembers [this mountain] ever emitting flame, but from time to time it produces subterranean thunders, as has happened in August 1818. At that time, the mountain thundered so strongly that a slight [earth] tremor was perceived and those living at Unalaska [settlement] believed that the nearby island of Amaxnax was breaking apart."
Grewingk (1850, translated 2003 by Fritz Jaensch) writes that Langsdorff and Krusenstern also report Makushin to have erupted strongly with flames in 1818. However, Grewingk (1850, translated 2003 by Fritz Jaensch) adds a footnote stating that this report "is an error. It was probably meant to mean, 'in smoke.' Characteristic of the Makushin Volcano is that it does not erupt in flames, this according to all other reports, including Cook's (from 1778)."

Grewingk (1850, translated 2003 by Fritz Jaensch) wrote that Postels reported two strong earthquakes in June, 1826, and Makushin erupted in flames. Grewingk (1850, translated 2003 by Fritz Jaensch) adds a footnote stating that this report "is an error. It was probably meant to mean, 'in smoke.' Characteristic of the Makushin Volcano is that it does not erupt in flames, this according to all other reports, including Cook's (from 1778)."
Litke (1835, translated in 1987) reported that Makushin was smoking on September 1, 1828.

Grewingk (1850, translated 2003 by Fritz Jaensch) writes that in 1836, Makushin was smoking. Dall (1870), Davidson (1884), and Plummer (1898) report that Makushin was smoking in 1838.

Grewingk (1850, translated 2003 by Fritz Jaensch) writes that Voznesenskii reported smoke from Makushin in 1843 and 1844. Beginning with Coats (1950), other compilers list the date for this eruption as being 1845. All previous compilers (except Doroshin (1870) - he lists 1845 as the eruption date) list 1843 or 1844 as eruption dates. Perhaps there was a second episode of smoking at Makushin in 1845, or perhaps there is a typographical error in Doroshin or Coats. Jacob and Hauksson (1983) and Arce (1983) include both 1844 and 1845 as eruptions.

Dall (1870) reports Makushin was active in 1865. Beget and others (2000) interpret this as Makushin was smoking.

Davidson (1884) climbed Makushin in 1867. On September 8, 1867, his party was ascending Makushin: "At 9:30 a.m. they reached the base of a very steep mountain, which we afterwards saw from the vessel, its almost perpendicular, black, scarred front looking like a great fortress on the outer flank of the snow-covered mountains. At its base the herbage was removed, and the earth at six inches below the surface was so hot that no one could bear his hands in it. The surface was cool; but, curiously enough, no one thought of observing the temperatures." At 9 a.m. on September 9, the expedition reached the crater: "For a few minutes the clouds broke away, and almost beneath the party lay the crater, rolling out volumes of smoke and yellow sulfurous vapors."

Becker (1898) writes that Makushin steamed from 1871-1874. This activity probably does not constitute a volcanic eruption.

Petroff (1884) reports that Veniaminov reported earthquakes at Makushin in 1880. This is certainly an error, as Veniaminof died in 1879. Becker (1898) reports Makushin was steaming during 1880. It is uncertain if the steam and earthquake are associated with a volcanic eruption from Makushin in 1880.

Becker (1883) reports an ash eruption from Makushin in 1883.

Becker (1898) reported steam from Makushin in 1891. This activity probably does not constitute a volcanic eruption.

Cordeiro (1910) climbed Makushin in July 1892 and reported that the crater was smoking, and that there were yellow sulfur crystals being formed. This activity may not constitute a volcanic eruption.

Becker (1898) reported steam from Makushin in 1895. This activity probably does not constitute a volcanic eruption.

Jaggar (1908) climbed Makushin on July 3, 1907 and reported: "The rim of the crater was finally reached at 12:45. Within was an expanse of snow, probably two miles in diameter, through which three or four steaming vents have maintained openings. Here we encountered fog and rain lifting and closing at intervals. We saw a steaming cavity ahead to the right. Examination proved this to be a new crater opening which was unknown to the guide, therefore it was promptly named the "Technology Crater" of Makushin. It is a vertical cavity in the snow, 75 feet in diameter, with a 300-foot wall of bedded ice and snow behind it and sulphurous steam incessantly rising through it. A great tumble of snow or ice blocks rests in front of it, and, where the steam drifts across these, their white surfaces are yellowed with sulphur." This crater is located between the central cone and the north rim of the caldera.
He also reported that the larger crater of Makushin contained very active solfataras on its northern side, and they also found a 15-foot diameter area of boiling mud.

The logbook of the USS Thetis (then the US Revenue Cutter Service Thetis) also records an eruption from Makushin during 1907. On Sept 1, 1907, they were anchored in Unalaska, and wrote "Between 5-00 and 5-30, heard two distinct explosions supposed to be from Makushin volcano. At 5-30, a thick shower of cinders and ashes from Mt. Makushin swept over the harbor and continued until 6-30, when light rain set in. Vessel covered with thin coat of cinders and ashes. Washed down decks and paint work. At 8-00, light shower of ashes from volcano again swept over harbor continued generally until midnight." The logbook record is viewable at the OldWeather project: oldweather.s3.amazonaws.com/ow…
As the weather for that day was recorded as east-south-easterlies all day, their supposition that the eruption originated from Makushin is the most likely. Thank you to the OldWeather project for transcribing this logbook and notifying AVO of the eruption account.

Coats (1950) reports smoke from Makushin in 1912.

Jaggar (1927): "A dispatch from Dutch Harbor of December 31, 1926, states that Mount Makushin, on Unalaska in the Aleutian Islands, erupted the evening of December 30 with 'fountains of fire and masses of vapor,' making a spectacular display. A slight earthquake accompanied the eruption and there was fear for the safety of Makushin village."

Coats (1950) reports an ash eruption from Makushin in October, 1938. However, the Anchorage Daily Times, in October 1938 reports that the Coast and Geodetic Survey was in the Aleutian Islands during the summer of 1938, and that the crew reported "the most violent eruption with great clouds of smoke rising from its crater." Therefore it seems likely that the previously cited October date for this eruption is inaccurate and that the observed volcanic activity actually took place sometime during the summer.

Jacob and Hauksson (1983) report that there was strong thermal activity (on N flank?) of central cone, caldera wall, and onto caldera flank during September, 1944.

From Jones (1952): "December 20, 1951 - A high column of white smoke (steam) rose above the summit of Makushin volcano, Unalaska Island, and the snow on the volcano was gray with ash."

Powers (1958) reports Makushin was smoking in 1952.

Powers (1953) reports steaming from Makushin in December, 1953. Barnett (1963) writes that he climbed Makushin either in the summer of 1953 or 1954 (article is unclear) and witnessed steaming, "snow grey from wind-carried ash thrown from the active crater," a sulfur smell, and boiling mud pots. This activity probably does not constitute a volcanic eruption. Snyder (1954) writes: "On March 2 [1953] Richard McDonald, U.S. Geological Survey seismologist stationed at Adak, rode a Navy plane from Kodiak to Adak and back. He reported steam rising from Pavlof, Shishaldin, Makushin, and a small cone within Okmok Caldera on this day."

From Shackleford (1982): "Observations in early July 1980 at Makushin by personnel from Lamont-Doherty Geological Observatory found a new explosion crater on the central cone within the caldera, some 60 m below the cone's summit. From this new vent tephra (presumably lithic in nature) extended in streaks on the snow's surface to the southeast. Some of the ejected blocks created impact craters 30-60 m from the crater. This minor explosive event was not witnessed, but obviously took place only shortly before the date of observation. It certainly took place within the last year, but Spring 1980 is deemed a likely date for this event. Otherwise, observations in July 1980 found 10 vents liberating steam and H2S on the summit of the central cone."
From Smithsonian Institution (1980): "On 8 July, J. Hauptmann, G. Gunther, and R. [Steuer] visited a seismic station on the E flank and overflew the summit. More than ten roughly circular vents emitted vapor from the summit area, a flat region about 100 m across. The largest vent was about 30 m in diameter, and others were around 10 m across. An H2S odor was detected, but no ash or incandescent material was observed.
"About 60 m below the summit on the S flank, an explosion vent had recently ejected tephra ranging in size from ash to blocks, deposited in streaks aligned roughly toward the SE. Some impact craters were present in the deposit area, which extended 30-60 m from the vent."

From Reeder (1989): "At 1900LT 28 April 1986, James Dickson, a resident of Unalaska, while on a Peninsula Airways Inc. flight from Dutch Harbor to Atka, observed a 500 m vertical steam plume over Makushin Volcano. The top of this plume trailed to the S for at least 40 km. James detected no obvious ash in the white steam plume. Pilot Tom Madsen, President of Aleutian Air Ltd. at Dutch Harbor, also flew to Atka from Dutch Harbor earlier the same day (left Dutch Harbor about 1120LT), but the volcano at that time was not visible due to cloud cover."
This activity probably does not constitute a volcanic eruption, and Simkin and Siebert (1994) classify this event as not an eruption. Additional reports are quoted below.
From Smithsonian Institution (1986, v. 11, n. 6): "On 28 April at 0700, James Dickson observed a 450 m vertical steam plume over Makushin that trailed SE for at least 30 km. He detected no ash in the plume."
From Smithsonian Institution (1986, v. 11, n. 4): "On 20 December, pilot T. Madsen (Aleutian Air) noticed anomalous amounts of steam rising from six large and closely spaced steam vents just E of the summit. The largest plume was 500-600 m high. No ash was observed in the white plumes. Air temperature at 2,400 m was -6.7°C, warm for that altitude. Steaming remained anomalously vigorous for the next two days before returning to a more normal level. Based on John Reeder's observations . . . since 1979, the summit steam activity is continuous and normally reaches heights of 100 m or slightly less."

From Reeder (1990): "Steam emissions were continuous from a large solfatara field near the summit of Makushin Volcano during 1987. Larger than normal steam-blast eruptions were observed on 1 and 2 February and again with some particulate matter on 1 and 2 March as described below.
"The crew (Hall Ostbevik and others) of the 40 m Great Pacific fishing boat observed in the afternoon of 1 February as they were going E toward Dutch Harbor above average continuous steam emissions from Makushin, Akutan, and Shishaldin volcanoes. On the evening of 1 February, Shawn Richardson, a resident of Dutch Harbor, observed from Dutch Harbor above average continuous steam emissions from the top of Makushin Volcano, which she estimated reached 600 m above the top of the volcano and which appeared like a large vertical mushroom white cloud. Such continuous above average steam-blast activity continued throughout 2 February up to at least 1430LT ( = GMT - 9 hours) when clouds obscured the volcano.
"At 1845LT 1 March, Benny Golodoff, Suzi Dengler, and Tom Madsen, all of Dutch Harbor, observed from Dutch Harbor a steam plume with minor particulate matter that extended at least 30 km at an unknown altitude to E from the summit of the volcano. Midday on 2 March, pilot Harold E. Wilson of Peninsula Airways observed several up to 250 m high steam plumes from the summit of the volcano with traces of particulate matter that had also drifted at least 3 km to WNW. He also observed particulate matter (possibly ash) over snow in the summit region of the volcano."

From Neal and others (1996): "On September 14, National Wildlife Service (NWS) relayed three pilot reports of sulfur smell northwest of Dutch Harbor and one veteran pilot report of "a trace of ash" at 4000 feet. Subsequent investigation turned up the fact that, over the past month, pilots had frequently smelled sulfur and seen "smoke and steam" from Makushin, as well as snow apparently darkened by ash. A similar report was called into AVO on September 23. On November 5, 1993, AVO received a report from NWS relaying a USCG cutter sighting of eruptive activity at 0930 Aleutian Standard Time. AVO and NWS examined available satellite imagery and found no anomaly; calls to residents of Dutch Harbor/Unalaska confirmed no ashfall. A NOTAM was issued by NWS. As phreatic activity is typical at Makushin, AVO distributed no formal information releases at any time."

From Neal and others (1995): "On January 19, AVO received a pilot report of two distinct steam plumes, possibly containing ash, rising about 1,000 m (3,280 ft) above the summit of Makushin Volcano. AVO received at least one phone call from a major air carrier and one from the U.S. Air Force about the report. The NWS issued a SIGMET.
"On January 21, an AVO staff member received a phone call from the Alaska Department of Emergency Services (DES) at 10:45 pm AST. The Chief of Police in Unalaska had contacted the DES to report a strong sulfur smell and unusual lightning. In addition to speaking to the Unalaska Chief of Police, AVO made phone contact with NWS watch officers to obtain satellite information and discussed possible scenarios with DES. It was concluded that the lightning was related to a strong frontal system and associated westerly winds. Additional reports of a robust steam plume were received on January 26.
"AVO frequently receives reports of increased steaming at Makushin Volcano. Some observations suggest a small amount of ash is contained in these steam plumes; this is likely the result of vigorous fumarolic or minor phreatic activity."
The Smithsonian Institution (1994) reports this event as a false eruption report caused by a storm.

From McGimsey and Neal (1996): "On 12:46 pm AST on Monday, January 30, 1995, USCG C-130 pilots reported a small steam and ash cloud from Makushin Volcano. The cloud rose to about 2400 m (8000 ft) and was carried northeast from the volcano, prompting NWS to issue a SIGMET that ran until 5 pm AST. Over the next hour, several pilots reported seeing a dispersing light brown ash plume at Makushin. All activity subsided shortly thereafter as confirmed by a satellite image recorded at 1:45 pm AST, which showed no sign of the eruption."

From McGimsey and others (2004): "On February 22, 2001, pilot Joe Polanco reported smelling sulfur and seeing steam issuing from the summit area of Makushin as he flew by. Over the next several months, as tremor from the eruption of Cleveland volcano, 230 km (~145 mi) to the west was being recorded on the Makushin network, AVO seismologists began to suspect that some of the seismicity was actually being generated at Makushin. By May, 2001, it was determined that a real increase in seismic activity beneath Makushin had begun in July, 2000, and on June 1, 2001, AVO included Makushin in the Weekly Update. Earthquakes ranging in magnitude from 0 to 1.5 were occurring at a depth of between 0 and 8 km. AVO continued to closely monitor the activity, which became intermittent by mid-summer and slowly faded back down to background levels through the fall months."

From Neal and others (2011): "On June 27, a USCG officer made a report to NOAA about a persistent area of discolored seawater in Unalaska Bay, about 3 km (1.9 mi) north of Dutch Harbor and in-line with Wide Bay cone and Table Top volcano, two satellite vents that are part of the larger Makushin volcanic field (McConnell and others, 1998). The officer stated that he had noticed this discoloration for approximately 2 years. NOAA forwarded the report and photographs via email to AVO on July 2.
"AVO considered three possibilities for the discoloration: (1) ship discharge, (2) hydrothermal venting from a submarine volcanic cone, and (3) groundwater discharge or venting through the seafloor. A transient ship discharge was quickly ruled out, due to the phenomenon’s consistent presence and location. Discriminating between a volcanic or groundwater explanation for the discoloration is difficult without further investigation. Unalaska Bay is a normal location for seismic activity, and a quick examination of AVO’s seismic data for the area revealed nothing beyond background. On July 11, the NOAA ship Oscar Dyson conducted a conductivity, temperature, and depth (CDT) study near the site, and on July 24, the NOAA ship Fairweather conducted another CDT study and bathymetric mapping. The Oscar Dyson’s CTD study detected nothing unusual but the study was done too far from the apparent source to rule out a possible hydrothermal plume. The Fairweather’s survey showed seafloor mounds in the vicinity, possibly emitting plumes, but not directly under the anomaly. Conductivity and temperature measurements did not support a volcanic source. Further data collection and analysis in August by NOAA showed numerous sites of probable bubble streams coming out on the seafloor (seen in 2007 imagery). Another NOAA ship reported similar discolored water in a different, but nearby location in July 2008. At this time, we conclude that the multiple locations of discolored water at the surface and at the seafloor point to likely groundwater discharge, possibly through a fault system, rather than a submarine volcanic plume."

From Neal and others (2014): "Low level seismicity was recorded at Makushin Volcano throughout 2010. At about 7:00 p.m. Alaska Standard Time on February 17, a veteran pilot noted an unusual dark plume over the volcano during exceptionally clear conditions. Later, Guardian Flight paramedic Wayne Boots sent AVO images of strong fumarolic output at the Makushin summit from February 19. AVO reviewed seismic data and saw no change of any significance related to a possible plume. On February 24, a strong vapor plume was visible with satellite imagery but again, no change in seismicity was noted. On March 3, AVO satellite analysts reported slightly elevated temperatures in the vicinity of the summit craters; not an unusual observation for the fumarolically active summit of Makushin.
Seismicity increased slightly with a small swarm on April 7 and again in May. AVO did not elevate the Aviation Color Code or Alert Level for Makushin for either of these slight departures from background."

From Dixon and others (2015): "No eruptive activity occurred at Makushin Volcano in 2013, but increases in seismicity and reports of possible ash plumes prompted increased AVO attention. The Makushin seismograph network periodically recorded tremor episode during 2013, likely unrelated to volcanism. Short swarms of earthquakes are common near Makushin. Four such swarms were noted in the last one-half of the year on August 28, September 24, October 29, and December 25 (fig. 35 in original text). A single observation of a small steam plume was noted in a clear Web camera image of Makushin on March 24 (fig. 36 in original text). The Aviation Color Code and Volcano Alert Level remained GREEN/NORMAL throughout the year."

From Cameron and others (2020): "Earthquake swarms are common at Makushin Volcano, and nine short earthquake swarms occurred in 2016. Most swarms comprised fewer than two dozen earthquakes each. Prominent swarms occurred on February 7, April 12, August 26, September 21, September 24, November 15, November 27, and December 26 (fig. 26). During all of 2016, the Aviation Color Code and Volcanic Alert Level remained at GREEN and NORMAL respectively."

From Orr and others, 2023: "Earthquake swarms are common at Makushin Volcano and several took place in 2019. Most swarms consisted of fewer than 10 events each; however, two more prominent swarms (on May 15 and June 18) contained more than 40 events each. Earthquakes in both swarms were located at depths of 5-10 km. The May 15 swarm comprised 45 earthquakes, located 17 km [10.6 mi] east of the volcano’s summit, and the June 18 swarm comprised 66 earthquakes, located 1-3 km southeast of the summit. A third, smaller swarm of 19 earthquakes took place on June 22, at similar depths to the earlier swarms and 11-12 km east-southeast of the summit. The Aviation Color Code and Volcanic Alert Level of Makushin Volcano remained at GREEN and NORMAL throughout the year."