Transition Zones

Transition Zones. Arid East Meets Maritime West. Gray clouds, heavy with moisture from an absorbent journey across the ocean, drizzle inland from west to east. Bumping into the Cascade Mountains, the rise, cool, and drop a final deluge that soaks the fir forests on the west facing slopes. , East of the protective Cascade Range, the sky is less cloudy and the plateaus are drier. Upland ponderosa pine woodlands descend to oak savannah, and then to desert sage and grassland. , The Columbia River Gorge is a meeting place of worlds separated by the Cascade Mountains. It boast five distinct "vegetation zones." plant communities adapted to the local climate., 14" Average Annual Rainfall , the hills are high and rugid a few scattering trees to be seen on them either small pine or scrubey white oke. &c.&c. - William Clark, October 21st, Monday 1805, near present-day John Day River , , 31" Average Annual Rainfall , The Countrey on each side begin to be thicker timbered with Pine and low white Oake." - William Clark, October 29, Tuesday 1805, near present-day Klickitat River , 36" Average Annual Rainfall , The Countary a high mountain on each side thickly covered with timber, such as spurs, Pine, Cedar, Oake Cotton - William Clark, October 30th, Wednesday, 1805, near present-day Cascade Locks , .