Built in Ylojarvi, Finland, from 1992 to 1996, it consists of a handmade hill covered with trees arranged in a mathematically determined spiral pattern. Each tree has been planted by a volunteer who has been contractually granted ownership of it, valid for four centuries, and transferable generationally. The larger idea behind the arrangement is straightforward: Conservation is both an individual and collective responsibility, extending far into the future.

Photographs of “Tree Mountain” are in the show, as are plans for other projects that still exist only on paper or as models. One is for a system of artificial dunes to protect the storm-wracked Rockaways in Queens, N.Y . Another is for an air-cleansing virgin forest to be planted on landfill also in Queens. A third, and probably the least likely to be given the go-ahead any time soon, is for a Peace Park in Washington, D.C.

The qualities that distinguish such work from 1960s and ’70s Land Art, with which Ms. Denes has sometimes been associated, are the same qualities that mark her drawings: a combination of moral rigor and an uninvasive lightness of touch. And what separates her work from object-fixated, dollar-value art of the 21st century is an insistence on impermanence. (That the retrospective is happening in the cash-buttressed fortress of Hudson Yards is an irony surely not lost on her.)

Positioned almost in the center of the fourth-floor galleries is a 1969 installation called “Human Dust.” It has two main components. One is a poster-size wall text telling the story of an unnamed man’s life. “He was an artist,” it begins. “He was born fifty years ago, which means he lived app. 2/3 of his expected life span.” We get statistics: the number of his close relationships, the number of places he lived. We learn details of his appetite (“During his lifetime he consumed 4800 lbs. of bread, 140 gallons of wine”), and of his character (“He was unhappy and lonely more often than not”). The account, basically an obituary, concludes: “34 people remembered him or spoke of him after his death and his remains shown here represent 1/85 of his entire body.”

The remains are indeed on display: a clear glass bowl filled with fragmented bones.

As if in response to this somewhat unnerving memorial, the galleries on the second floor, where the show concludes, have a dusky chapel-like atmosphere. Many of the most extravagantly imagined late drawings are here, as is a model of the Queens forest, financed by the Shed, and two sculptures , also commissioned by the Shed for the show.