Around the year 1316 King Edward II, an enthusiastic hunter, expanded his royal deer park to include new areas of Sherwood Forest, near Clipstone, Nottinghamshire, effectively shutting off the means of subsistence to the locals who depended on the resources of the forest for their livelihoods. Subsequent petitions from the commoners were unavailing. The incident is most likely the source of the legends of Robin Hood – think of him as an English Paul Bunyan or Pretty Boy Floyd – who raffishly tweaks the nose of the authoritarian establishment.

Domination of rich forest land was the prerogative of nobility and royalty not only in England, but all across Europe. So imagine the sense of wonder of the early European migrants to North America when they discovered a virtually limitless blank slate of forest spread out in front of them. Trouble was, they were city folks, unaccustomed to sharing their environment with predators other than human, so they termed it “a howling wilderness” and determined to tame it. The natives, who lived well enough by a combination of hunting, gathering, and gardening, helped them survive long enough to get the hang of it. One of their favorite expressions, derived from the habit of turning their swine to forage for themselves during the warm months, was “Root hog, or die!”

To those early pioneers, the notion of setting aside land for parks would have been literally incomprehensible. But forward about a hundred years or so to the Industrial Revolution, and the percentage of citizens living in cities had grown, in relation to those still living on the land. Life in the big cities – New York, Chicago, Philadelphia – marked by overcrowding, crime, poor sanitation, and the absence of settings for outdoor recreation (think of “recreation” in terms of its root) was not conducive to the happiness or growth of those unable to get away from it.

Frederick Law Olmsted, who lived from 1822 to 1903, was perfectly positioned in time to exploit the general impulse of city-dwellers toward outdoor recreation. He was also situated geographically – on Staten Island, and acquainted among the New York City gentry – to oversee the creation of “natural” parkland. Philosophically, he contributed to the conservation movement that during the latter years of his life advocated the preservation of, for example, the setting of Niagara Falls; the Adirondack Park, with its sections designated “forever wild,” and the national park system championed by Teddy Roosevelt and turning 100 years old in 2016 His best-known designs are New York City’s Central Park and Boston’s Emerald Necklace, both of which preserved land that was being grossly misused or was doomed for development, and instead created green spaces amid the bustle that Olmsted could perceive approaching.

As a child, looking out the large windows of our fourth-floor flat in Albany, I couldn’t see a blade of grass. Brick buildings, cobblestone streets (soon to be paved over), slate sidewalks, and trees planted in gaps in the sidewalks were the total scene. I don’t recall yearning for anything else, but did love the weekly walk in Washington Park, with its lakehouse, bridge, and gardens only two blocks away and inspired by Olmsted designs. But our lives were there in the neighborhood, and the park was over there. It took me perhaps a decade to realize that over there was the place to be.

The life of John Muir, a Scottish immigrant, coincided with Olmsted’s. Muir’s focus was not at all on the creation of artificial spaces amid urban development, but on the preservation of the country’s spectacular natural wonders. Yosemite National Park is his masterpiece. The rest of our heritage has been celebrated recently by Ken Burns’ documentary series The National Parks; America’s Best Idea. From Acadia to Yellowstone (both, interestingly, sited upon volcanic zones, one ancient and quiescent and the other destined to blow spectacularly sooner or later), they represent how well we can do when we turn loose the better angels of our nature.

Three boyhood friends of mine and I, then already past middle age, hiked one day into the Pelican Creek Bear Management Area in Yellowstone. Signs dictated a minimum party size of four and daylight hour use only, and it was a hike of a few miles to the creek. But I will remember for the rest of my life one of those magical days of fishing: the cutthroats resting under the banks and darting out for our proffered flies; flocks of Canada geese watching us cautiously from far off; and in an unforgettable vignette, Professor Beak, up to his chest in willows and his rod bending to a good fish, with a huge bald eagle hovering fifty feet above him awaiting an opportunity. It was one of those rare days for which a fisherman spends a lifetime at his sport,

I’ll be heading tomorrow to the Adirondack Park to hike an old familiar valley where I lived sixty years ago. But this time I won’t be gazing speculatively at the peaks lining both sides; those days have pretty much passed. Still, on my modest afternoon walks in the park, I remember John Muir’s words – “In every walk with nature one receives far more than he seeks” – rejoice in the little fingerprints of a raccoon in streamside mud, listen to the drumming of a hairy woodpecker on a moribund white pine, reach reflexively for my left trousers pocket whenever I spy one of my friends, and know what he’s thinking: “Here comes the old guy with the cane and the treats!”