The serenity of Yellowstone Lake glows, as John Taliaferro writes, as "a diadem." But if private water developers in Idaho and Montana had had their way, this liquid centerpiece of Yellowstone would have been flooded under thanks to a dam built at the point where the Yellowstone River begins its flow toward Hayden Valley and an eventual tumble into the Grand Canyon of the Yellowstone. George Bird Grinnell played a crucial role in marshaling resistance. Had the dam been built, many favorite areas along the lake, including shoreside geysers, and important wildlife habitat, would have been submerged. Photo courtesy Neal Herbert/NPS