ougone, it appears, is due.

    “It may not feel like it, but you’re standing on t active volcano in tone National Park geologist, told me soon after climbing off an enormousorcycle and s at ters atMammot Springs early on a lovely morning in June. A native of Indiana, Doss is anamiable, soft-spoken, extremely tful man ail. A smallsappud graces one ear. A sligrains against his crisp Park Service uniform.

    employee. In fact,   t place into do it,”  off in a bouncy, battered four-o let me accompany  doing  is a park geologist does. t assignment today is to give anintroductory talk to a neour guides.

    Yelloone, I  out, is sensationally beautiful, atelymountains, bison-specked meadoumbling streams, a sky-blue lake, ing. “It really doesn’t get any better t,” Doss says. “You’vegot rocks up at Beartoot are nearly ters of to Eart mineral springs s at t springs from s title—“—or prettier.”

    “So you like it?” I say.

    “O,” y. “I mean I really love it ers are toug too , but ’s just—”

    errupted o point out a distant gap in a range of mountains to t, o vieains, old me, ins.

    “t gap is sixty or maybe seventy miles across. For a long time nobody could understandiansen realized t it o be because tains  bloy miles of mountains just obliterated,you knoty potent. It took Ciansen six years to figureit all out.”

    I asked  caused Yelloone to blow w did.

    “Don’t knorange t understandt all. Vesuvius, in Italy, ive for til an eruption in 1944and t just