Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred installing pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred with President Lubbers after installing pendulum sculpture in Kirkhof, 1975.

Artist Dale Eldred's assistant installing sand to pendulum sculpture in Kirkhof, 1975.

Black and white photograph of the falls from Artist's Point at Yellowstone National Park (mile 17601).

Black and white photograph of a group of young men holding signs and candles at night during the artists' protest parade in New York City, New York. Scanned from the negative.

Black and white photograph of a man smiling while holding a candle in the middle of a crowd during the artists' protest parade at night in New York City, New York. Scanned from the negative.

Black and white photograph of a group of men smiling and holding candles during the artists' protest parade at night in New York City, New York. Scanned from the negative.

Black and white photograph of a group of protestors smiling and singing while holding posters and candles during the artists' protest parade at night in New York City, New York. Scanned from the negative.

Black and white photograph of a group of men holding posters and candles at night during the artists' protest parade in New York City, New York. Scanned from the negative.

Black and white photograph of a protestor with a poster hung around his neck, a cigarette in his mouth, and a candle in his hand during the artists' protest parade at night in New York City, New York. Scanned from the negative.

Black and white photograph of a group of protestors walking down the street during the artists' protest parade at night in New York City, New York. In the photograph, a man is playing a wooden flute in the foreground. Scanned from the negative.

Black and white photograph of a group of protestors walking down the street during the artists' protest parade at night in New York City, New York. In the photograph, a young man and woman are walking together in the foreground and the woman is seen…

Black and white photograph of a bearded man walking outside during the artists' protest parade at night in New York City, New York. Scanned from the negative.

Black and white photograph of a group of protestors walking down the street during the artists' protest parade at night in New York City, New York. In the photograph, a group of men are seen standing outside on the citystreet and wearing protest…

Black and white photograph of a group of young men and women walking down the street holding candles and posters during the artists' protest parade at night in New York City, New York.

Black and white photograph of a group of protestors walking down the street during the artists' protest parade at night in New York City, New York. In the photograph, the protestors are seen standing outside on the citystreet and two men are holding…

Black and white photograph of a man holding an umbrella and a protest poster during the artists' protest parade in New York City, New York. Scanned from the negative.