The concept of an “Okanogan Highlands” flora has come into common usage to describe as many as six roughly co-eval Middle Eocene lacustrine floras extending from Northern Central Washington into Central British Columbia. While early publications exist for the Eocene localities of British Columbia, only Republic and Princeton have recent, detailed floral descriptions on which to base comparisons. We have begun a comprehensive investigation of the McAbee site, near Kamloops, British Columbia. Megafossils and pollen are used to infer climate and compare the flora found at the McAbee site to that at Republic and Princeton as well as approximately co-eval lowland assemblages in the Puget Group and Chuckanut formations. Conifers are common and diverse at McAbee, with at least twelve separate taxa present. There are also at least twenty two angiosperm genera with many yet to be described. The dominant dicot leaf taxon at McAbee is Fagus which is also represented by nuts and cupules. The confirmation of Fagus, also recognized from Princeton and Republic, provides the oldest well documented occurrence of the genus, predating the early Oligocene records of Fagus previously reported for North America, Asia and Europe. McAbee apparently lacks thermophilic elements such as Sabal, found at Princeton or Ensete and Dioon found at Republic. It also appears to lack the diversity seen at Republic, although this may be an artifact of the intensive public collecting done there in recent years. In summary, the McAbee site appears to be a good fit overall for the Okanogan Highlands floral construct but also has unique elements that expand our knowledge of the Middle Eocene flora of the Pacific Northwest.

Key words: Eocene, Fagaceae, McAbee, Middle, paleobotany, tertiary