|Comments:||[original comment maintained, striken through which no longer applies] |Something just to the left of Grotto Fountain's position from cam. Very dense plume developed 1218:22 and was dissolving by 1219:56, with the bulk confined to the first 45s or so. Still some steam flurries after 1219:56. Based on Heinrich's comment and overnight capture of East Sentinel's major (thanks for the flashlight, Graham), this was an East Sentinel minor. I will note that each other minor that was captured did not appear this voluminous in steam formation (in fact those had steam which I would otherwise not seek anything behind) - only the major topped it. Alignment and trees seem to suggest something in the Chain Lakes, though I wouldn't particularly rule out Spa even if the plume seems on the large and dense side of things.