Rocks are dominated by Eocene sea floor deposits and basalt flows from ancient sea floor spreading. Slopes are steep and soils are generally poor, supporting predominantly coniferous forests C. Climate 1. Rainfall patterns dominated by the influence of the Pacific ocean, combined with elevational influences of uplifted mountains. Moist air rises over the higher mountains and cools, lowering the dew point and releasing more precipitation. High pressure systems dominate in the late spring, summer, and early fall and maintain much dryer, warmer weather.
Net result is period of extremely wet weather followed by a summer drought.
Temperature a. Also dominated by the influence of the Pacific Ocean. Large mass of water tends to cool very warm air and warm very cold air as it passes over. Result is less extreme temperature fluctuations daily and seasonally than those seen in the interior. Sitka spruce belt immediately adjacent to the coastline, western hemlock is climax tree further inland, Douglas fir is the dominant conifer in most areas as a result of fires and logging., understory of Oregon grape, salal. Open, south facing slopes.