Just prior to his departure, at 7 p.m. on the evening of May 17, 13½ hours before the eruption, Glicken took the famous photograph of Johnston sitting by the observation-post trailer with a notebook on his lap, smiling.
5月17日の夕刻、出発直前の午後7時、噴火の13時間半前、グリッケンは観測所のトレーラーの横に腰掛けてノートを手に笑みを浮かべたジョンストンの、後日有名となる写真を撮影した。