Dorothy Olga Johansen was born in Seaside, Oregon, on May 19, 1904. She was the daughter of John H. Johansen of Germany and Sophie (Binder) Johansen of Astoria, Oregon. She graduated from Astoria High School in January, 1922, and from the Oregon Normal School, Monmouth (now Western Oregon University), two years later. She taught school for eight years, in rural Klamath County, in Seaside and Corvallis, Oregon, and in Yakima, Washington, before enrolling in Reed College.

Following her graduation from Reed College in 1933, she was appointed a graduate assistant in Reed’s history department and five years later was advanced to the rank of instructor. Meanwhile, she received her M.A. in 1935, and her Ph.D. in history from the University of Washington in 1941.

Dorothy Johansen taught extension classes at the Portland Extension of the University of Oregon, and at the University of Washington summer schools. For eight years she served on the Board of Directors of the Portland Public Schools and was instrumental in the school’s adoption of a gifted child program. She was a member of the Board of Directors of the Oregon Historical Society and a member of the editorial board of the Pacific Historical Review, the Citizen’s Advisory Committee, the Juvenile Court and Home Circuit Court, State of Oregon.

Johansen published many books, articles, and reviews. She was co-author with Professor Charles M. Gates (University of Washington), of Empire of the Columbia (Harper, 1957), edited and wrote the notes and introduction for Robert Newell’s Memoranda (Champoeg Press, 1959); edited Voyage of the Columbia (Champoeg Press, 1960), and served as general editor, for the Beaver Book Series. Johansen was named Oregon Woman of the Year in 1957 by Theta Sigma Phi. On leave in 1958-59 from Reed College to prepare a history of Reed’s early years supported by a grant from the Ford Foundation, she produced a detailed unpublished study of the first eight years of the college (1911-1919).

Promoted through Reed’s academic ranks, ultimately to Professor of History and Humanities, Johansen retired in 1969 after thirty-one years in the classroom. She continued to serve the college as official archivist until 1984. In 1973, Reed awarded her an honorary Doctor of Humane Letters, as tribute to her continuing service.

She died in Portland, Oregon, on December 13, 1999.