All of Pepper's sculptures from the beginning of her sculptural career were displayed outdoors. Eventually, she began her experiments using earth to contain a sculpture. "In the seventies I developed the concept of "Earthbound Sculptures", that is sculptures seemingly born in or rising up from the earth." Becoming more involved with her native New York in the 1970s, her progressive ideas became realized in commissions such as her seminal work "Amphisculpture" (1974-76). Furthering her vocabulary in steel, throughout this time period she used Cor-ten steel. While working at a U.S. steel factory in Conshohocken, Pennsylvania, she was given Cor-ten steel. Relishing the exposed rusted surfaces of Cor-ten, she made pieces like "Dallas Land Canal" (1971-75). She was, in fact, one of the first artists, if not the first, to incorporate Cor-Ten steel into sculpture. Beginning in the 1970s, and to the present day, she has lived a bi-continental life traveling between Europe and the United States.