Walter Joseph De Maria[1] (October 1, 1935 – July 25, 2013)[2] was an American artist, sculptor, illustrator and composer, who lived and worked in New York City.

In 1960, De Maria and his friends, the avant-garde composers La Monte Young and Terry Riley, participated in happenings and theatrical productions in the San Francisco area.

[4] From his exposure to the work of La Monte Young and dancer Simone Forti, among others, De Maria developed an interest in task-oriented, game-like projects that resulted in viewer-interactive sculptures.

De Maria briefly ran a gallery on Great Jones Street in lower Manhattan with his wife Susanna, showing Joseph Cornell's collection of rare films, Robert Whitman's Happenings (he was then married to and created with dancer/artist Simone Forti), and exhibiting De Maria's Minimalist sculptures made of wood.

[9] In 1980, De Maria bought a four-story, 16,400-square-foot Con Edison substation at 421 East Sixth Street, and an adjacent lot at No.

He realized Land art projects in the deserts of the south-west US, with the aim of creating situations where the landscape and nature, light and weather would become an intense, physical and psychic experience.

Vertical Earth Kilometer is a one-kilometer-long brass rod, two inches in diameter, drilled into Friedrichsplatz Park in central Kassel, Germany.

[16] In 1979, De Maria meticulously arranged five hundred brass rods for The Broken Kilometer, a permanent installation at 393 West Broadway in New York.

The Broken Kilometer is also part of De Maria's series of monumental sculptures using a horizontal format, which feature groupings of elements ordered according to precise calculations.

[18] One Sun/34 Moons (2002), conceived by the artist in collaboration with architect Steven Holl, was opened 2007 at the Nelson-Atkins Museum of Art, Kansas City.

(Its owner soon became better known with the Paula Cooper Gallery)[1] De Maria avoided participating in museum shows when he could, preferring to create his installations outdoors or at unconventional urban locations.

[20] In 1968 and 1977, De Maria participated in Documenta in Kassel; he installed his permanent public sculpture Vertical Earth Kilometer in the city's Friedrichsplatz Park.

[21] Organized by the Menil Collection in 2011, "Walter De Maria: Trilogies" was the artist's first major museum exhibition in the United States.

[22][23][24][25][26][27] Set in the desolate desert spaces of the American southwest, this feature documentary film contains rare footage of De Maria and the artist's extant and non-extant works.