Shotwell, J. Arnold2016-08-012016-08-011967-0600786047https://hdl.handle.net/1794/2000044 pagesSamples of Peromyscus from six late Tertiary localities in Oregon are described. Variation and progressive changes are discussed for the time, Barstovian through Hemphillian. Two new species, P. pagei and P. valensis are described. The diversity of late Tertiary species in Oregon and the Northern Great Basin is compared with that of living species in North America today.en-USCreative Commons BY-NC-ND 4.0-USPeromyscusBarstovianHemphillianP. pageiP. valensisNorthern Great BasinArticle