ABSTRACT
On the evening of 19 September 1870, a group of adventurers relaxed around a campfire at the junction of the Firehole and Gibbon Rivers in the Yellowstone region of the western US. They were members of the Washburn Expedition, a group of businessmen, local officials and journalists accompanied by a small army escort that had come south from Helena in Montana. Their adventure was stimulated by the reports from an earlier smaller expedition and following its directions they had encountered waterfalls, canyons, hot springs and mud pools. Turning for home, they unexpectedly stumbled into the Upper Geyser Basin, which had not been found by their predecessors. This contained, they estimated, nearly a hundred geysers – larger and higher than any they had seen previously (and including what would become known as Old Faithful).
