Mont Blanc massif led to calls to limit access to the most popular summits and for the mountains to be treated with greater respect. The Mont Blanc massif has provided numerous opportunities for academic research, dating back to the very first ascent of Mont Blanc in 1786 during which Michel Paccard carried scientific equipment to confirm it as the highest summit. In 1820, an ill-fated expedition led by Dr Hamel included pigeons intended for release at varying altitudes to measure the impact of reduced air density on their ability to fly. In 1890, Joseph Vallot built a small meteorological observatory at approximately between
1986 K2 disaster an avalanche on 21 June. Pennington's body was pulled out by climbers who had witnessed the incident, but Smolich's body has yet to be found. The rest of the team left the mountain shortly after the accident. On 23 June, French climbers Liliane and Maurice Barrard reached the summit, just 30 minutes after their teammate Wanda Rutkiewicz became the first woman to summit K2. Both Liliane Barrard and Rutkiewicz were climbing without bottled oxygen. As darkness fell, all three, along with team member Michel Parmentier and two Spanish climbers, Mari Abrego and Josema Casimiro, had to make an emergency bivouac