[5] He produced drawings and collage works that incorporated images from natural history, science fiction films, classical art, religious iconography, and pornography including "homoerotic clippings from beefcake magazines".

Smithson became affiliated with artists who were identified with the minimalist or Primary Structures movement, such as Nancy Holt (whom he married), Robert Morris and Sol LeWitt.

[10] In 1967 Smithson began exploring industrial areas around New Jersey and was fascinated by the sight of dump trucks excavating tons of earth and rock that he described in an essay as the equivalents of the monuments of antiquity.

[9] This resulted in the series of 'non-sites' in which earth and rocks collected from a specific area are installed in the gallery as sculptures, often combined with mirrors or glass.

Works from this period include Eight-Part Piece (Cayuga Salt Mine Project) (1969) and Map of Broken Clear Glass (Atlantis) (1969).

[9] The journeys he undertook were central to his practice as an artist, and his non-site sculptures often included maps and aerial photos of a particular location, as well as the geological artifacts displaced from those sites.

Smithson was interested in challenging the prevalent conception of Central Park as an outdated 19th-century picturesque aesthetic in landscape architecture that had a static relationship within the continuously evolving urban fabric of New York City.

[9] Now the Ramble has grown up into an urban jungle, and lurking in its thickets are "hoods, hobos, hustlers, and homosexuals," and other estranged creatures of the city ....

In the spillway that pours out of the Wollman Memorial Ice Rink, I noticed a metal grocery cart and a trash basket half-submerged in the water.

[12] While Smithson did not find "beauty" in the evidence of abuse and neglect, he did see the state of things as demonstrative of the continually transforming relationships between humans and landscape.

[18] While in earlier 18th-century formal characterizations of the pastoral and the sublime, something like a "gash in the ground" or pile of rocks, if encountered by a "leveling improver", as described by Price, would have been smoothed over and the area terraformed into a more aesthetically pleasing contour.

[19] For Smithson, it was not necessary that the disruption become a visual aspect of a landscape; by his anti-formalist logic, more important was the temporal scar worked over by natural or human intervention.

He saw parallels to Olmsted's Central Park as a "sylvan" green overlay on the depleted landscape that preceded his Central Park [20] Defending himself against allegations that he and other earth artists "cut and gouge the land like Army engineers", Smithson, in his own essay, charges that one of such opinions "failed to recognize the possibility of a direct organic manipulation of the land.." and would "turn his back on the contradictions that inhabit our landscapes".

[23] The work consisted of a derelict woodshed on campus that he covered with earth until the central beam broke, illustrating the concept of entropy.

An informational plaque is located in a small wooded area immediately behind the Liquid Crystal Institute building on the Kent State University main campus.

Between 1966 and 1967 he produced Proposals for the Dallas-Fort Worth Regional Airport as concepts for "aerial art", monumental-scaled earthworks to be seen by air travelers.

[10] On July 20, 1973, Smithson, a photographer and the pilot died in a light aircraft crash while inspecting the site of Amarillo Ramp on the ranch of Stanley Marsh 3 near Amarillo, Texas, in a Beechcraft Baron E55; the National Transportation Safety Board attributed the accident to the pilot's failure to maintain airspeed, with distraction being a contributing factor.

Artists Tacita Dean, Sam Durant, Renée Green, Lee Ranaldo, Vik Muniz, Mike Nelson, and the Bruce High Quality Foundation have all made homages to Smithson's works.