Okanagan Highlands refers to an arc of Eocene lakebed sites that extend from Smithers in the north, down to the fossil site of Republic Washington.
The grouping includes the fossil sites of Driftwood Canyon, Quilchena, Allenby, Tranquille, McAbee, Princeton and Republic.
These fossil sites range in time from Early to Middle Eocene, and the fossil they contain give us a snapshot of what was happening in this part of the world because of the varied plant fossils they contain.
We can infer the difference in climates between the sites. McAbee was not as warm as some of the other Middle Eocene sites, a fact inferred by what we see and what is conspicuously missing. In looking at the plant species, it has been suggested that the area of McAbee had a more temperate climate, slightly cooler and wetter than other Eocene sites to the south at Princeton, British Columbia and Republic and Chuckanut, Washington. Missing are the tropical Sabal (palm), seen at Princeton and the impressive Ensete (banana) and Zamiaceae (cycad) found at Republic in north-central Washington, in the Swauk Formation near Skykomish and the Chuckanut Formation of northern Washington state.