In South America, Ojos del Salado involves a short scramble while Aconcagua is just a walk. Horrell acknowledged that Ojos del Salado was more technically difficult, but considered Aconcagua a greater challenge because of physical demands. Aconcagua's base camp, at , is accessible by mule, but from that point on, climbers must carry all of their supplies to as many as three higher camps before the final ascent. By contrast, Ojos del Salado is accessible by four-wheel-drive vehicles up to ; from that point on, climbers need only carry supplies to a mountain hut at before making their final push to the summit.