>>510398631 (OP)Middle Miocene Climatic Optimum, oh no
Overall, Western North America north of 40° N was wetter than south of 40° N.[18] The interior Pacific Northwest experienced a dramatic increase in precipitation during the MMCO around 15.1 Ma.[19] In contrast, the Mojave region of western North America exhibited a drying trend.[20] Along the New Jersey shelf, the MMCO did not result in any discernable climatic signal relative to earlier or later climatic intervals of the Miocene; temperatures here may have been kept low by an uplift of the Appalachian Mountains.[21]