D.A. Davidson & Co. Share: Financial services D.A. Davidson & Co. Visit Website 0305 5th Street Lewiston, ID 83501 (208) 743-0818 (208) 798-0626 (fax) About About Providing high-quality investment products and services to individual investors for over 60 years. Largest full-service investment firm in the Pacific Northwest, managing more than $20 billion.