On vanishing in the age of surveillance

Contemplating the mystery of those who have gone missing and remembering a lost friend

Looking out into the La Plata Mountains, where two runners have vanished in the last year. Jonathan P. Thompson photo.

At about 6:30 p.m. on Saturday, June 24, Ian O’Brien texted his partner Beth Henshaw, letting her know he had summited Dibe Nitsaa — or Hesperus Mountain — in the La Plata Mountains of southwestern Colorado. He then began the several-mi…