Nicolas Grevet  •  Photography

Near the summit of the Haleakalā volcano in Maui, Hawaii, the thin air and the possibility of dehydration at that elevation makes hiking more challenging than one might expect. This is aggravated by the fact that trails lead downhill from parking areas into the crater. Because of this, hikers are faced with a difficult return ascent after potentially descending 2,000 feet (610 m) or more to the crater floor via the Keoneheʻeheʻe (Sliding Sands) Trail.