The valley is sealed off by the Cascade Selection towards the northeast and because of the Klamath Mountains on the northwest. Inside the far north the terrain is rugged and greatly forested, getting wetter within the coastal aspect and drier and barren in the upper northeast. During the south the Central Valley is shut off via the transverse range

The valley is sealed off with the Cascade Range on the northeast and from the Klamath Mountains on the northwest. In the much north the terrain is rugged and intensely forested, turning out to be wetter to the coastal facet and drier and barren in the higher northeast. From the south the Central Valley is shut off through the transverse ranges, mos