News of the California Gold Rush sparked Bigelow's interest in relocating to the Pacific Coast.
In 1851 Bigelow joined a wagon train headed west and crossed the Oregon Trail with his law books and desk, arriving in Portland in September.
After determining Portland already had enough lawyers, he sailed up the coast in the schooner Exact to Puget Sound in November 1851 on the same voyage that carried the Denny Party.
Daniel served as the first Treasurer of Thurston County, a member of the first legislature of Washington Territory in 1854, the first Superintendent of the Olympia School, and President of the Board of Trustees of Puget Sound Wesleyan Institute, the forerunner of the University of Puget Sound.
Daniel Bigelow died September 15, 1905, at Olympia, the last surviving member of the first territorial legislature.