Open-file Report O-08-14, Preliminary Geologic Maps of the Corvallis, Wren, and Marys Peak 7.5’ Quadrangles, Benton, Lincoln, and Linn Counties. Rocks within this mapped area reveal a rich and turbulent geologic history beginning about 50 million years ago that includes tropical islands, volcanic eruptions and epic floods. Publisher: DOGAMI CD-ROM Price: $ 10.00