dynamics between positive forms and negative space. His Adjacent, Against, Upon (1976) juxtaposes three large granite slabs in different relationships to cast concrete forms; the 30-50 ton granite slabs were quarried in the Cascade Mountain Range and transported by barge and train to Myrtle Edwards Park. For Displaced/Replaced Mass (1969/1977), later installed outside the Marina del Rey, California, home of Roy and Carol Doumani, he planted four granite boulders of different sizes from the High Sierra into lid-less concrete boxes in the earth so that the tops of the rocks are roughly level with the ground. For a 1982 work at the former IBM Building in New York, Heizer sheared off the top of a large rock and cut grooves into the surface before setting it on supports hidden within a stainless steel structure. Designed as a fountain, the boulder appears to float over running water. He called it Levitated Mass, a title he would use again in future. Commissioned by the president of the Ottawa Silica Company, the Effigy Tumuli earthwork in Illinois is composed of five abstract animal earthworks reclaiming the site of an abandoned surface coal mine along the Illinois River; the shapes (1983–85)—a frog, a water strider, a catfish, a turtle, and a snake—reflect the environment of the site, which overlooks the river. In 2012, Heizer completed Levitated Mass (2012). On permanent installation at Los Angeles County Museum of Art, Levitated Mass is a massive white, diorite boulder (21.5 feet wide and 21.5 feet high) that sits atop a 456-foot-long sloped walkway, allowing viewers to experience the weight of the rock as they walk through the empty space below. It took eleven nights, from February 28 to March 10, 2012, to move the 340-ton rock from Jurupa Valley to the museum. The installation is situated in a field of polished concrete slices, set at a slight angle between the Resnick Pavilion and Sixth Street. Heizer opened the exhibit on June 24, 2012. A feature documentary, also named Levitated Mass, was directed and edited by the filmmaker Doug Pray. It details the making of the sculpture as it relates to Heizer's career while portraying the boulder's 105-mile journey through Los Angeles and the public's reaction to its installation. Other recent public artworks by Michael Heizer include Tangential Circular Negative Line in Mauvoisin, Switzerland, commissioned by Fondation Air&Art directed by Jean Maurice Varone, as well as Collapse (1967/2016)