"The Long Path is a 358-mile hiking trail that begins at the 175th Street subway station in Manhattan and runs to Thacher State Park, just south of the Adirondack Mountains."

" Conceived around 1930 by Vincent Schaefer, a chemist and meteorologist, and named after a line from a Walt Whitman poem, the Long Path initially had no fixed route and was essentially a sequence of waypoints that led toward the Adirondack High Peaks.... It often felt like I was the only human on the trail. Occasionally I encountered others in the mornings or evenings, though all of them lived nearby and were being towed by their dogs. I began to realize that nobody I encountered was aware of the Long Path’s existence, including several people whose homes sat mere feet from the trail. Despite being well marked (its route is indicated with a rectangular aqua blaze), it appears to be hidden in plain sight. Apparently the ubiquitous patches of paint adorning tree trunks, stones and telephone poles are only perceptible to those who navigate by them...."

Writes Casey Kelbaugh, in "Walking From Manhattan to the Catskills on the ‘Long Path’/Intrigued by a trail marker he spotted upstate, a photographer set out to follow a meandering — and little-known — hiking route north from New York City" (NYT)(free access link).

The Walt Whitman poem is "Song of the Open Road," which begins:

Afoot and light-hearted I take to the open road,
Healthy, free, the world before me,
The long brown path before me leading wherever I choose.

Henceforth I ask not good-fortune, I myself am good-fortune,
Henceforth I whimper no more, postpone no more, need nothing,
Done with indoor complaints, libraries, querulous criticisms,
Strong and content I travel the open road....

It ends, many lines later:

Camerado, I give you my hand!
I give you my love more precious than money,
I give you myself before preaching or law;
Will you give me yourself? will you come travel with me?

Shall we stick by each other as long as we live?