Ancient Lake Clarkia was formed 15.78 million years ago when a Priest Rapids flow of the Wanapum Formation of the Columbia River Flood Basalts dammed the ancient St. Maries River near Clarkia, Idaho. The Clarkia Fossil Beds contain exceptionally preserved fish, plants, and palynomorph fossils that record high temperatures of the Mid-Miocene Climatic Optimum. While there has been extensive macrofossil and palynomorph work done on the P-33 and P-37 localities over the last 60 years, neither has been performed on the P-40 locality due to poor access to the site. Here, we have performed palynomorph and macrofossil analysis of a 10 cm x 30 cm x 30 cm section of the P-40 site. This is the first study to be done comparing the differences between the plant macro- and microfossil assemblages of the P-40 locality.  Preliminary results show that the macrofossils represent the near-shore plant assemblages of the mixed mesophytic forest, with the microfossils representing the regional flora around the lake.