A descendent of Oregon pioneers, Helen Althaus was a pioneer woman lawyer. Her legal career included public service, private practice, and work in environmental policy for the Bonneville Power Administration and the U.S. Fish and Wildlife Service. She practiced law during a period when there were very few women lawyers in Oregon, and she was the first woman to serve as a clerk for a federal judge in Oregon. Throughout her career, she was active both in professional and public service.

Helen Florence Althaus was born on March 26, 1910, in Bluffton, Ohio. Her mother, Lenore Lorain Williams, was a descendent of Elijah Williams, an Ohio lawyer who took his family to Oregon in 1851. Her father, Amos C. Althaus, was a member of the Swiss Mennonite community in Bluffton. In 1911, the family moved to Oregon, where Helen Althaus was raised on the Sweet Briar Farm in Troutdale. She attended Gresham Union High School, graduating in 1927, and majored in chemistry at the University of Oregon, where she was elected to Phi Beta Kappa. After receiving her degree in 1932, she worked as an analytical chemist, including time at the Troutdale aluminum plant owned by the Aluminum Company of America (Alcoa). On June 6, 1943, the Sunday Oregon Journal reported that she was "Alcoa's oldest graduate chemist (in point of service but certainly not in years)" and "a peach of a chemist, too, company officials say."

While working at the plant she attended the Northwest School of Law (now the Lewis & Clark School of Law). She received her law degree in 1945 and was admitted to the Oregon bar the same year, when she was thirty-five years old. She worked as a clerk for U.S. District Judge James Alger Fee from 1947 to 1949 and was deputy city attorney for Portland from 1949 to 1953. In 1953, she was hired as an associate at King, Miller, Anderson, Nash and Yerke (now Miller Nash). Early in her career, she was identified on the letterhead by her initials, H. F. Althaus. Eventually, the firm put her full name on the letterhead and the door. She worked at King Miller until 1970 but never became a partner. During the time she worked at King Miller, no large Portland firm accepted a woman as a partner.

In 1970, Althaus established her own practice, first in Tigard and then in Raleigh Hills, with partners Gladys Everett and Virginia Renwick. She joined the Bonneville Power Administration in 1973 to work on national environmental policy and later became a staff attorney for the U.S. Fish & Wildlife Service. Her book on Public Trust Rights was published by the Fish & Wildlife Service in 1978.

Althaus was active in efforts to protect human rights through such organizations as the National Lawyers Committee Against United States Intervention in Central America, the United Nations Association, and the American Civil Liberties Union. In 1997, the ACLU of Oregon presented her with an award for “significant contributions to the causes of individual freedom.” As a member of the Oregon Bar World Peace Through Law Committee, she did extensive research on international justice systems. During her last years at King Miller, she applied for admission to the Portland City Club, which at the time only had male members. Her application was rejected but helped pave the way for the eventual admission of women in 1973. As a member of the women's legal fraternal organization, Phi Delta Delta (merged with Phi Alpha Delta in 1972), she argued for the removal of the restriction that allowed only Christians to join.

Althaus was a strong advocate for the advancement of women in the legal profession. In 1948, she was a founder of the Queen's Bench, the Multnomah County Chapter of Oregon Women Lawyers (OWLS), and served as its president in 1973. During the early 1980s, she was a member of the Multnomah Bar Association’s first Committee on the Status of Women and was the first woman member of the Oregon State Bar’s Continuing Legal Education Committee. In 1994, Oregon Women Lawyers honored her with the Justice Betty Roberts Award for her support and encouragement of women in the legal profession.

While practicing law in Portland, Althaus lived on Sweet Briar Farm in Troutdale, where she raised Great Danes and horses and went horseback riding almost every evening. She served on the Troutdale City Council and the Parks Advisory Committee from 1973 to 1982. The Helen Althaus Park in Troutdale was named for her when she retired from public service in 1982.

Althaus and her mother had begun to attend plays at the Oregon Shakespeare Festival in the early 1950s, and in 1985 she moved to Ashland. She was a generous supporter of the Festival and its actors through the Southampton Legacy Society and had a front-row seat for OSF plays. She also acted on stage for local theater groups. 

Helen Althaus died in Ashland on February 2, 2006, at the age of ninety-five.