After hiking around the McAbee Hills, I climbed onto the hills at the same elevation as the McAbee Site to look for fossils and uncovered a few:

The McAbee fossils have been dated at 53 million years old and these were found at the same elevation (but 1+ km east) so we can assume they are about the same age.   Metasequioa and alder leaves can be identified among the 7 impressions.