Yosemite National Park is amazing and unique. It is no wonder that John Muir was so enchanted with the area. The park contains redwoods, waterfalls, rivers, and spectacular cliffs. The most popular area is in a valley, surrounded by cliffs on both sides.
Shortly after the park was established, Congress allowed its Hetch Hetchy valley to be dammed, for water for San Francisco. This was a blow to Muir, and deprived us, according to him, of more spectacular scenery.
John Muir was a scientist who did much of his scientific work in nature. He wasn't a college professor, nor did he work as a researcher for the government, or for some company, on a regular basis. He observed, and he wrote. He didn't just describe, he taught (he was said to be especially good at teaching children about nature in ways they could understand) and he advocated. One of the things he advocated most strongly was the establishment of Yosemite. Muir was a Christian, and probably one of those who really do communicate with God in natural surroundings on a regular basis.
This is the next-to-last sentence of Muir's The Yosemite:
These temple destroyers, devotees of ravaging commercialism, seem tohave a perfect contempt for Nature, and, instead of lifting their eyesto the God of the mountains, lift them to the Almighty Dollar.
Here's a paragraph from his The Mountains of California:
In the morning everything is joyous and bright, the delicious purple ofthe dawn changes softly to daffodil yellow and white; while the sunbeamspouring through the passes between the peaks give a margin of gold toeach of them. Then the spires of the firs in the hollows of the middleregion catch the glow, and your camp grove is filled with light. Thebirds begin to stir, seeking sunny branches on the edge of the meadowfor sun-baths after the cold night, and looking for their breakfasts,every one of them as fresh as a lily and as charmingly arrayed.Innumerable insects begin to dance, the deer withdraw from the openglades and ridge-tops to their leafy hiding-places in the chaparral, theflowers open and straighten their petals as the dew vanishes, every pulse beats high, every life-cell rejoices, the very rocks seem totingle with life, and God is felt brooding over everything great and small.
We recently visited part of the park. The area is, indeed, beautiful. There are redwood trees, the spectacular valley, equally spectacular mountains, and some beautiful water features. Yosemite is not far, an hour's drive or so, from Fresno, CA, a city of roughly half million. Fresno is in the San Joaquin Valley, which is both one of most intensely farmed areas in the U. S., and also one of the most heavily polluted and transformed from its natural state. Why didn't Muir try to preserve more of this valley? Perhaps because it was flat, therefore less attractive than the mountains. Perhaps Muir knew that trying to preserve this area would have been a losing battle, more difficult than preserving Yosemite.
Muir's activity wasn't confined to the West. He was born in Scotland, but emigrated to Wisconsin as a boy, with his family, and lived and worked in the Eastern part of the U. S. Several of his works are available from Project Gutenberg. His Thousand-Mile Walk to the Gulf is available from the Sierra Club. He walked from Louisville, KY, to Florida.