The Oregon state flag was adopted in 1925 and is the only U.S. state flag that displays different images on front and back. The flag has gold lettering and symbols on a field of navy blue (blue and gold are Oregon's state colors). The flag's face displays part of the state seal and the words STATE OF OREGON 1859 (the year Oregon was admitted to the Union). The parade flag (or "dress flag") has a gold fringe, but the utility flag has a plain border.

The symbols on the shield include the mountains and forests of Oregon, an elk with branching antlers, a covered wagon and ox team, the Pacific Ocean with a setting sun, a departing British man-of-war ship (a symbol of the departure of British influence in the region) and an arriving American merchant ship (a symbol of the rise of American power). The 33 stars supporting the shield signify that Oregon was the 33rd state to join the Union.

The reverse of the flag pictures Oregon's official state animal - the beaver. Oregon's nickname is The Beaver State (stemming from the early 19th century when fur hats were fashionable and Oregon’s streams were an important source of beaver).

Source:

State Flag: Oregon Blue Book

Links:

State Flags - 50 states List
National Flag