This is a questionable event.
|Start:||December 1876 ||Observed|
|Debris-avalanche, volcanic avalanche, or landslide: ||
|Lahar, debris-flow, or mudflow: ||
|MaxVEI: ||3 ||
Becker (1898) lists an eruption from Iliamna in 1876. Sapper (1917) and Coats (1950) call this eruption "smoke." However, Kienle and Swanson (1983) report this eruption as a "major eruption spreading ash to Kenai Peninsula (Rymer and Sims, 1976). The description for this 1876 eruption sounds similar to the description of the 1867 eruption. Waythomas and Miller (1999) suggest that perhaps this event was a flank collapse, with debris avalanches and lahars.
Miller and others (1998) doubt the veracity of this eruption: "although Coats (1950) lists several reports of 'smoke', and an eruption in 1867, documentation is poor and validity of the reports is questionable. Except for the summit fumarolic activity, it is uncertain and perhaps unlikely that Iliamna Volcano has been historically active."
Perhaps 1867 and 1876 refer to two separate events, or perhaps someone has reversed a "76" or a "67" somewhere along the way. It is interesting to note that although Becker lists the 1876 event, he does not list the 1867 event.