Benguet Road construction crews setting explosives on a sheer cliff of the Bued River Canyon near Camp 5 in Tuba, Benguet
<a href="https://en.wikipedia.org/wiki/Dean_Conant_Worcester" class="extiw" title="w:Dean Conant Worcester">w:Dean Conant Worcester</a>
The Philippines, Past and Present by Dean Worcester, 1914