S241 (B3 I41–42)
F: /
B: /
[Michael Heizer, Dissipate, 1968, five trenches dug in Black Rock Desert, Nevada.
A view of Heizer’s work available here.]

S561 (B4 I93–94)
F: /
B: /
[Michael Heizer, Double Negative, 1969, 240,000-ton displacement of rhyolite and sandstone, Mormon Mesa, Overton, Nevada.
A view of Heizer’s work available (as Fig. 7) here.]