William Spencer Mason (May 25, 1832 – March 27, 1899)[2] served as mayor of Portland, Oregon, from 1891 to 1894 and 1898 to 1899.

[4] From humble origins, he began his career in railroads in the South and Midwest, continuing in San Francisco in the early 1870s, where he helped organize street railway companies.

After moving to the Northwest, he helped construct the Northern Pacific line between Tacoma and Seattle.

[2] He devoted most of his fortune, and his wife's, to paying the depositors of the Portland National Bank during the Panic of 1893.

Born in England and married once before, in Napa, California, she donated the property now known as Willamette Park to the City of Portland, where the Water Bureau's pumping station, dedicated in 2017, bears her name.