The life of the Mountain Man was a constant struggle with the forces
of nature. There was an unremitting interaction between the Mountain Man
and such practical advantages of civilization as he was able to bring with
him, and the powerful forces of the environment. He was able, by tremendous
exertion, to exploit the great resources of fur-bearing animals in the
mountain west efficiently enough to render a profit to the companies and
to make a living for himself. He had no thought of conservation yet it
cannot be said that these species, or any other, were ever in danger of
extinction. 
He brought supplies to the mountains by pack animals and later by wagon train in sufficient quantity to furnish not only himself but the Indians with superior weapons and traps to aid his quest for furs but it was done at the cost of greatly reducing the profit to be gained. He explored thoroughly the whole of the far West rendering possible the future waves of economic development such as mining, stock raising and agriculture but at the cost of ending his own way of life.
It must be realized that the environmental forces were so powerful as to compel the Mountain Man to modify greatly his own way of life. He could have a family life only by marriage with an Indian woman. He had to adopt the Indian practice of moving with the seasons and often with the food supply as well. He had to forget many of his own habits and learn from the Indians. On balance, it must be concluded that both the Mountain Man and his environment forced temporary changes and adjustments from one another but that neither had a permanent advantage.
The Mountain Man was sometimes a conscious but perhaps more often an unconscious agent of Manifest Destiny. If he survived to old age he was apt to reflect on the course of his life with some satisfaction, for he could feel that he had been an active participant in the growth, expansion, and development of his country. He was conscious that he had seen much progress and had helped to bring it about. At the same time, he was very likely to view his years as a Mountain Man with a certain feeling of nostalgia. He was inclined to forget the physical hardships, the inflated prices, and the extreme danger and remember with pleasure the high adventure, the freedom of choice, the closeness to nature and the good comradeship of his early days. He had been to far places, seen and done remarkable things.
Broken Hand