In summer 2012, Garrett Beckwith and his 19-year-old daughter, Della, set out for Wyoming’s remote Mount Hooker.

Both devoted climbers, they saw the trip as a chance to test limits and share the bond forged on countless outdoor adventures. Rising nearly 12,500 feet, Mount Hooker is among the continent’s most forbidding climbs—isolated, weather-beaten, and merciless.

Garrett and Della were last seen beginning their ascent. When they failed to return, an intensive search unfolded, but no trace was ever discovered. Theories range from hidden falls to storms forcing them astray, but the mystery remains. For loved ones, the silence is unbearable. Yet Garrett and Della are remembered for how they lived: bound by love, wilderness, and adventure.