Robert Angus Duncan was born in Ann Arbor, Michigan, in 1946. In 1948, his family relocated to Oregon, and settled in Medford a few years later. In 1967, he earned a degree in government from Harvard University. From 1974 to 1979, he served as an aide to Portland Mayor Neil Goldschmidt, and continued to assist Goldschmidt in the U.S. Department of Transportation from 1979 to 1980. He participated in the creation of the 1980 Northwest Power Act. During the 1980s, he worked in the private sector for various renewable energy companies, and in 1990, he became a member of the Northwest Power Planning Council, now known as the Northwest Power and Conservation Council. He served as chair from 1994 to 1995.

The Northwest Power Planning Council is a four-state regional planning body formed by Congress through the Northwest Power Act of 1980 to develop and maintain regional conservation and electric power plans and a fish and wildlife program. The council is composed of two representatives from each member state: Oregon, Washington, Idaho, and Montana. The mission of the council is "to preserve the benefits of the Columbia River for future generations." The body was originally known as the Pacific Northwest Electric Power and Conservation Planning Council; the name was shortened to Northwest Power Planning Council in October 1981, and in 2003, the name was changed to the Northwest Power and Conservation Council.