Devil's Postpile National Monument was once part of Yosemite National Park. The discovery of gold in 1905 near Mammoth Lakes prompted a boundary change that left the Postpile on adjacent public land.
A proposal to build a hydroelectric dam called for blasting the Postpile into the river. Influential Californians persuaded the federal government to stop the demolition and in 1911, President William Howard Taft protected the area as a National Monument.
Shari and I visited the Postpile for the first time in late October. I noticed this evening that the National Monument is closed for the season. We evidently couldn't have had better timing to get a Fall visit in.
Devil's Postpile National Monument, Madera County, California 2012