Additionally two important non-compression biotas are present in the Eocene Okanagan Highlands. A permineralized chert flora, the Princeton Chert is found along the Similkameen River interbedded with coal deposits of the Ashnola shale unit, Allenby Formation known for anatomically preserved plants. In the Central sites, subbituminous coal of the Hat Creek Coal Formation around Hat Creek hosts an amber biota, the Hat Creek amber which preserves many small insects and plant fragments that would likely not be found in the compression biotas.
