Hah! It's great to see others that have learned to sail on the Columbia too! I spent almost all my free time sailing the Columbia with my dad when I was a kid and still sail it frequently out of Cascade Locks. I have only sailed the areas between Astoria and The Dalles but would like to take a trip up to the bridge (somewhere along the Oregon Idaho border?).
Like someone said before the currents below the dams and wind conditions in the Gorge can be a bit tricky but the Columbia River Gorge is truly a sight to behold. Surprisingly the sailing can get intense. I have seen quite possibly 5-6ft swells and 40+ knot winds sailing wing/wing up to Hood River. The trip back into the wind was brutal. Motor running and comming out of the water, 2 reefs in the main and the headsail reefed way in. The waves were only about a boat length from crest to crest so we were pounded pretty hard.
It is a neat river to explore really. My only problem is I want to go somewhere other than just East or West on the same section of river I have been sailing for 23yrs! If you do decide to take a trip on the Columbia (especially the Gorge) I am sure you will enjoy it.