IN the final part of this trilogy about the life and works and influence of John Muir, I will deal with the staggering achievements of this great Scotsman and show how he changed the world by preserving large tracts of wilderness and preaching the virtues of conservation and environmentalism.

Last week we saw how an accident in 1867 had left him temporarily blinded, and it truly was a life-changing event because he emerged from the darkness into a new-born light. Muir had always been a practical person with a nascent spirituality, but now that aspect of his character came to the fore. He had long believed in seeing God in nature, and laying aside the strict Presbyterianism of his father, that belief underpinned everything he would do for the rest of his life.

READ MORE: The wild youth of legendary Scottish naturalist John Muir

By the summer of 1867, Muir knew what he wanted to do. On September 1, he set out to walk from Kentucky to Florida, a journey of 1000 miles, and later recorded his experiences in the book A Thousand-Mile Walk to the Gulf. In his notebook made on the journey, he famously wrote it was by “John Muir, Earth-planet, Universe”.

He had no designated route: “My plan was simply to push on in a general southward direction by the wildest, leafiest, and least trodden way I could find, promising the greatest extent of virgin forest.”

One of the first places he called at was Glasgow – that’s Glasgow, Kentucky – noting “Glasgow is one of the few Southern towns that shows ordinary American life.”

He was able to stay with farmers for most of his trip, and otherwise slept rough, including several nights in a graveyard. You may recall how a near-drowning as a boy had made him resolve to become a strong swimmer, and that proved a life-saver when he was almost swept away in the Chattahoochee river.

His descriptions of the swamps and marshes of Florida are the stuff of literature: “What a landscape! Only palms as far as the eye could reach! Smooth pillars rising from the grass, each capped with a sphere of leaves, shining in the sun as bright as a star.”

All the while he was noting and sketching plants – now he really was a botanist. He was also developing his conservationism, witnessing a deer hunt and writing: “Well, I have precious little sympathy for the selfish propriety of civilized man, and if a war of races should occur between the wild beasts and Lord Man, I would be tempted to sympathize with the bears.”

No sooner had he reached his destination Cedar Keys in late October, than Muir had an attack of malarial fever and almost died. It took him until January to recover, after which he made a brief visit to Cuba where again he noted plants and trees before a chance encounter with a sea captain persuaded him to take ship for New York and then on to California where he made a home of sorts in San Francisco.

He didn’t stay long, walking to Yosemite valley which, on the order of the late President Abraham Lincoln, was already classed as a State Park – the first time the US Federal Government had ordered a wilderness area to be set aside for preservation. Muir was in raptures at what he found, and promptly moved to Yosemite and built himself a log cabin. We can still read his account of that first visit on the website of the Sierra Club, and I urge you to do so as you will find lyrical descriptions of the majesty of Yosemite.

The next year he found work as a summer shepherd in the high Sierra Nevada mountains, all the while developing his skills as a botanist and geologist – the branch of science which he came to love.

Muir could see the mountains of the Sierra Nevada all around, noting: “To lovers of the wild, these mountains are not a hundred miles away. Their spiritual power and the goodness of the sky make them near, as a circle of friends ... You cannot feel yourself out of doors; plain, sky, and mountains ray beauty which you feel. You bathe in these spirit-beams, turning round and round, as if warming at a camp-fire. Presently you lose consciousness of your own separate existence: you blend with the landscape, and become part and parcel of nature.”

In 1870, at the age of 32, Muir moved to Yosemite full-time, mainly working in a sawmill but also becoming renowned as a guide. In all he spent three years living in the valley and became something of a local celebrity as artists, celebrities and scientists went out of their way to meet the Scot whose knowledge of the local flora was unsurpassed, as was his ability as a guide.

Muir had been reading the works of the author, naturalist and philosopher Ralph Waldo Emerson and was hugely delighted when Emerson came to meet him during the author’s tour of the Western USA in 1871. He had been with Muir less than a day when he offered the Scot a teaching position at Harvard. Muir politely declined, but Emerson’s endorsement of his work was a major fillip to Muir.

The following year Muir met a fellow Scot, the artist William Keith who had been born in Oldmeldrum in Aberdeenshire in the same year as Muir was born in Dunbar.

They became lifelong friends, Keith’s spectacular paintings of the Californian wildernesses proving the perfect accompaniment to Muir’s musings. Theirs was a peculiarly Scottish friendship – they liked nothing better than flyting each other with insults.

The Californian wilderness proved a magnetic attraction for Muir and he began to compose articles about Yosemite and the Sierra Nevada mountains – many of which he personally climbed – which were published in newspapers and magazines. The timing was propitious, as in 1872 President Ulysses S Grant and the US Government had named Yellowstone as the country’s first National Park. Muir was to be one of the leaders of the successful campaign to have Yosemite given the same status, especially after he overturned the normal view that Yosemite had been created by earthquakes and showed that it was glaciation that had carved its landscape. Thanks to his writings, he was now seen as an authority on the wildernesses of the western USA.

His first major scientific paper on the Giant Sequoia tree was published in 1876, the same year that he gave his first public lecture in Sacramento which was on the subject of glaciation and which made a considerable impact at the time. He was now actively working for conservation, particularly of true wildernesses and treescapes.

READ MORE: Back in the Day: The accidental coming of light for John Muir

At the age of 41, he married Louisa Wanda Strenzel, who was then 33. Theirs would be a strange marriage, as he would spend the next ten years managing his father-in-law’s orchards in Martinez, California, but was often on expeditions to wilderness areas as far away as Alaska. They would have two children, Wanda and Helen, and the family home is now part of the John Muir National Historic Site.

In 1885, Muir had a premonition that his father Daniel was dying. He was able to gather the family at his father’s bedside in Kansas City, Missouri, where he died in his 82nd year on October 6. He would have a similar premonition about his mother Ann and reached her bedside before she died on June 23, 1896.

Muir wrote in his obituary of his father: “He seemed to care not at all what people would think of him. That never was taken into consideration when work was being planned.” He could have been writing about himself.

Robert Underwood Johnson, highly influential editor of Century magazine, met Muir and was hugely impressed with the Scot. In the late 1880s, he published two quite extraordinary articles by Muir which are credited with pushing the US Government to make Yosemite a National Park.

The template laid down by Muir for the park was followed in almost every way at Yosemite and was used for almost every other National Park – and there are 62 of them across 29 states with a further 419 locations designated as National Park sites.

Johnson and Muir also co-founded the Sierra Club, originally seen as an “Alpine club” for climbers in California. Muir became its first president in May 1892. He held the post for almost 20 years, and he is usually credited with being the founder, though other influential people such as William Keith were involved. The Club became the US’s premier conservation body and has branches across the States. It has a paid membership of 750,000, a staff of 600, a budget of nearly $100m and is recognised as the longest-established advocacy organisation for environmental causes.

If he had done nothing else, Muir could have retired knowing that he had set in train a Club that would continue his work to preserve wildernesses. He did lose one big campaign when the state government overrode his protests to create the Hetch Hetchy reservoir that drowned a valley that some said rivalled Yosemite for beauty.

In 1903, this lean Scot that some called “John of the Mountains” had a rather interesting companion on a trip into Yosemite – none other than President Theodore Roosevelt who as vice-president had stepped up the presidency when William McKinley was assassinated in 1901. Conservation-minded Roosevelt and Muir got on famously and spent one of their nights sleeping rough under the stars, an experience the president called “unforgettable”.

In that same year of 1903, Muir set out on a world tour, visiting London, Paris, Berlin, Russia, Finland, Siberia, Korea, Japan, China, India, Egypt, Ceylon, Australia, New Zealand, Malaya, Indonesia, the Philippines, Hong Kong and Hawaii, and while he also became a naturalised American citizen that year, Muir never forgot his Scottish roots, and once wrote of a scene in the Sierra that it was “a glorious wilderness that seemed to be calling with a thousand songful voices ... fold beyond fold of finely modeled hills and ridges rising into mountain-like masses in the distance, all covered with a shaggy growth of chaparral, mostly adenostoma, planted so marvelously close and even that it looks like soft, rich plush without a single tree or bare spot. As far as the eye can reach it extends, a heaving, swelling sea of green as regular and continuous as that produced by the heaths of Scotland.”

He did go home once, visiting Dunbar and Edinburgh in 1893 during a tour of Europe. The following year his first book The Mountains of California was published, and its success left the reading public clamouring for more. Soon the accolades followed, including honorary degrees for the man who, don’t forget, never graduated from Wisconsin State.

Muir was never the same man after his wife died in 1905, and increasingly devoted his time to writing books and articles and lobbying for environmental causes.

On a visit to his daughter, Muir contracted pneumonia. He died on December 24, 1914, in California Hospital, and was buried beside his beloved wife in the Muir/Strentzel gravesite in San Francisco.

His friend Robert Underwood Johnson wrote: “The world will look back to the time we live in and remember the voice of one crying in the wilderness and bless the name of John Muir ... He sung the glory of nature like another Psalmist, and, as a true artist, was unashamed of his emotions. His countrymen owe him gratitude as the pioneer of our system of national parks ... Muir’s writings and enthusiasm were the chief forces that inspired the movement. All the other torches were lighted from his.”

His legacy? Environmentalism, conservationism, National Parks and preserved wilderness across the world, and here in Scotland the invaluable work of the John Muir Trust. Can ye beat it?