Menan Buttes
Two cones of glassy lava are located directly south of here. The largest rises 800 feet above the surrounding plain.
Hot molten lava, erupting from great depth, met cold surface water in the wet flood plain of Snake river: the northern butte, in fact, formed in the channel of Henry’s fork, which was forced further east. Suddenly chilled into small particles of volcanic glass, the lava exploded up in a great spray of steam and solid fragments which built up into wind-blown cones around large summit craters a half mile long and 200 to 400 feet deep.
Text prepared by the Idaho Historical Society and the Idaho Geological Survey. Marker made and installed by the Idaho Transportation Department.
Submitted by @danbrekke