Mountain Madness interests. While leading Mountain Madness, Fischer became renowned for his ascents of the world's highest mountains made without the use of supplemental oxygen. Fischer and Wally Berg were the first Americans to summit Lhotse, the world's fourth highest mountain (27,940 feet / 8516 m), located next to Mount Everest. He and Ed Viesturs were the first Americans to summit K2, (28,251 feet / 8611m) in the Karakoram of Pakistan without supplemental oxygen. During his stewardship of Mountain Madness, Fischer led social and environmental initiatives to help people in the countries in which Mountain Madness traveled. As the leaders of the
Karakoram Highway Indus River at Thakot and continues along the river until Jaglot, where the Gilgit River joins the Indus River. This is where three great mountain ranges meet: the Hindukush, the Himalaya, and the Karakoram. The western end of the Himalayas, marked by the ninth highest peak in the world, Nanga Parbat, can be seen from the highway. The highway passes through the capital of Gilgit–Baltistan, Gilgit, and continues through the valleys of Nagar and Hunza, along the Hunza River. Some of the highest mountains and famous glaciers in the Karakoram can be seen in this section. The highway meets the