Recent rises in average temperatures have led to significant glacial retreat across the massif and an awareness of the need for better environmental protection, including a call for World Heritage Site status.

The Mont Blanc massif is 46 kilometres (29 mi) long and lies in a southwest to northeasterly direction across the borders of France (Haute-Savoie and Savoie), Italy (Aosta Valley) and Switzerland (western Valais).

However, the extreme western end of the southern side of the massif does lie within France and is bounded by the Vallée des Glaciers (which connects to the Val Veny over the watershed of the col de la Seigne), and its waters flow southwards towards the Isère and onwards to the Rhône.

It concerned three alpine guides who were buried in a crevasse during an avalanche on 20 August 1820 near the Rocher Rouges, high up on Mont Blanc, during an expedition organised by Joseph Hamel [de].

It was identified as that of a young Chamonix guide who had been caught in a winter storm during a solo ascent of the Nant Blanc face of the Aiguille Verte in 1982 and was assumed to have fallen into a crevasse.

[7]: 25 During the mid-19th century the granite of the Mont Blanc massif was an important source of stone for buildings; one hundred Italian stonemasons were brought to the Chamonix valley by Charles Albert of Sardinia for reconstructing the towns of Sallanches and Cluses, both of which had at that time just been destroyed by fires.

[38] The mountaineer and explorer, Edward Whymper, noted that the basin of the Glacier de Talèfre was "considered good hunting-ground for crystals", and that the slopes below les Courtes had yielded many large specimens.

[41][42][43][44] In order to preserve the mineralogical heritage of Mont Blanc, in 2008 the commune of Chamonix banned all mineral-hunting activities and collection of specimens without a prior permit being issued by the mayor's office.

Even on the high passes of the Tour du Mont Blanc, around 2,000 to 2,500 m (6,600 to 8,200 ft), summer temperatures can be between 5 and 15 °C (41 and 59 °F), but feeling much colder because of wind chill in windy or wet conditions.

[56] High up in the middle of the Glacier de Talèfre, completely surrounded by ice, and due south of Les Droites, lies a large triangular region of steep mountainside containing an unusual mixture of high-alpine vegetation.

[68] The region in which the Mont Blanc massif is located has been occupied by humans for at least 70,000 years,[69] although, as now—and because of the great height and glaciated nature of the mountains—only the lower parts of the valleys around its perimeter would have been inhabited or used as routes of communication.

[72] For many centuries thereafter, the settlements around the Mont Blanc massif comprised a rural population of peasant mountain farmers, living off animal husbandry, supplemented with a meagre harvest of rye and oats.

The many published accounts of climbs and impressive sights amongst or around the mountain range attracted numerous wealthy and notable visitors, for whom a visit to marvel at the Sea of Ice (the Mer de Glace) became a fashionable thing to experience.

The book concludes with Mont Blanc, a 144-line poem by Percy Shelley, written whilst in Chamonix and which was inspired by the river Arve, the snow-covered summits, the chaotic glaciers and the forests that he experienced during their visit.

[84] Far, far above, piercing the infinite sky, Mont Blanc appears—still, snowy, and serene— Its subject mountains their unearthly forms Pile around it, ice and rock; broad vales between Of frozen floods, unfathomable deeps, Blue as the overhanging heaven, that spread And wind among the accumulated steeps;

[87] When Savoy was eventually annexed to France in 1860, Napoleon III and Empress Eugénie visited the region to mark the event and undertook to enhance road access leading to the end of the Arve valley.

[85] The 19th century saw considerable economic development which turned the small agricultural town of Chamonix into a base for tourists, with luxurious hotels and mountain lodges being built to accommodate them.

[104] In recent years, guards have been placed on the most popular route of ascent to Mont Blanc's summit at peak periods in order to ensure that those entering the mountain environment are adequately equipped and skilled.

[15]: 97 [107] 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.

[108] In 1890, Joseph Vallot built a small meteorological observatory at approximately 4,350 m (14,272 ft) between the Dôme du Goûter and Mont Blanc's summit from where numerous measurements and scientific experiments were conducted.

[111][112] Three examples of modern-day uses of the high mountains for scientific research include neutrino detection, uranium pollution monitoring and climate change: A troop garrison, known as the Casermetta, was active for many years at the Col de la Seigne, on the border between France and Italy.

In the 1930s, during a period of increased international tension, the Mont Blanc massif was used by both countries wanting to demonstrate their military might, and large drills and troop exercises were undertaken at high altitude.

[3][139] At 3,300 m (10,827 ft), the summit station also provides relatively easy access for climbers to the northeastern peaks of the range, including short introductory rock scrambles and a simple ice-face route on the NW face of the Petite Aiguille Verte.

[151][155][156] Each high altitude hut faces its own individual challenges, often relating to water and energy supply or waste management, and the provision of services to visitors can sometimes conflict with environmental protection.

In 2007, it produced its position statement regarding the classification of Mont Blanc as a UNESCO World Heritage Site, and in 2009 a Transboundary Integrated Plan (PIT) was announced, with the implementation of six regional projects running until 2013.

[155] As a result of long delays, many environmental groups from France, Italy and Switzerland have worked together under the umbrella organisation, proMONT BLANC, to jointly raise concerns and to put pressure on national governments and the European Union to support and make quicker progress with World Heritage classification.

[166][167] ProMont Blanc also undertakes reviews of a suite of 24 environmental, 24 economic and 10 social indicators across 15 towns around the massif (seven French, five Italian and three Swiss), and monitors and reports on the effectiveness of measures intended to deliver sustainable development across the region.

[168] In October 2017 representatives from all three nations finally signed a joint declaration of intent as the first formal step towards submitting a bid for the Mont Blanc massif to be a candidate for inclusion on UNESCO's World Heritage Site list.

[169][170][171] All the French parts of the Mont Blanc massif, plus the neighbouring Aiguille Rouges range, have been listed as a Zone naturelle d'intérêt écologique, faunistique et floristique (ZNIEFF).

[61][63][174][175] Despite these individual designations, the Mont Blanc massif as a whole is still regarded by conservationists as representing an important missing link in the wider network of protected areas of the western Alps.