Strategy. Under normal circumstances, at least 80% of the Fund's net assets (plus any borrowings for investment purposes) will be invested in municipal securities that pay interest that is exempt from federal income tax, including the federal alternative minimum tax, and any applicable state income tax for individual residents of the state of Oregon (80% policy). The 80% policy is a fundamental investment policy that can only be changed upon shareholder approval. However, the Fund typically attempts to invest all of its assets in securities that pay interest that is exempt from federal income tax and state income tax for individual residents of such state, but may invest up to 20% of its net assets in securities that pay interest that … Show more… Under normal circumstances, at least 80% of the Fund's net assets (plus any borrowings for investment purposes) will be invested in municipal securities that pay interest that is exempt from federal income tax, including the federal alternative minimum tax, and any applicable state income tax for individual residents of the state of Oregon (80% policy). The 80% policy is a fundamental investment policy that can only be changed upon shareholder approval. However, the Fund typically attempts to invest all of its assets in securities that pay interest that is exempt from federal income tax and state income tax for individual residents of such state, but may invest up to 20% of its net assets in securities that pay interest that is subject to the federal alternative minimum tax. Such securities include obligations issued by municipalities and other authorities in Oregon and US possessions and territories. In certain cases, dividends paid by the Fund may also be exempt from local personal income taxes. The Fund primarily invests in high quality municipal securities that are rated as, or, if unrated, are determined by the Manager to be, investment grade at the time of purchase. The Fund may invest in securities insured against default by independent insurance companies and revenue bonds. The Fund may also invest in variable and floating rate securities, as well as interest rate swaps, futures and options on futures to hedge against interest rate changes and inverse floaters to produce income. To a lesser extent, the Fund may invest up to 20% of its net assets in high yield, below investment grade municipal bonds (commonly known as high yield or junk bonds). High yield bonds include those that are rated below Baa3 by Moodys Investors Service, Inc. or below BBB- by Standard & Poors and unrated bonds that are determined by the Manager to be of equivalent quality. When making investment decisions, the Manager focuses on bonds that it believes can generate attractive and consistent income. In selecting investments for the Fund, the Manager considers various factors, including: a securitys maturity, coupon, yield, credit quality, call protection and relative value and the outlook for interest rates and the economy. The Manager may sell a security for various reasons, including to replace it with a security that offers a higher yield or better value, respond to a deterioration in credit quality, or raise cash. The Manager generally considers any capital gains or losses that may be incurred upon the sale of an investment. In addition, the Manager considers the duration of the Funds portfolio when deciding whether to buy or sell a security. The Fund will generally have a dollar-weighted average effective maturity of between 5 and 30 years. Show less