The Green Truss section of the White Salmon is a classic Class V run in the Columbia Gorge. It has some big rapids and a handful of waterfalls. Every rapid is runnable but most people do a few portages.
It starts by parking by the Green Truss Bridge and lowering down ropes to the river. There is a good warm up before Big Brother, a big waterfall with a cave at the bottom. This is followed by Double Drop as well and Upper and Lower Zig Zag. BZ Falls is commonly portaged and near the end of the run.
Mile 0: Put-in at the Green Truss Bridge.
Mile 2.9: Upper Zig Zag (V) and Lower Zig Zag (V) are two of the most difficult rapids on the run.
Mile 3: Orletta Creek enters from the right. This is an alternate put-in or take-out if you don't mind hauling your boat through a creekbed for 15 minutes.
Mile 4: Triple Drop (IV) is an aptly named rapid.
Mile 4.9: The Flume (IV) is a hard rapid to describe. Be sure to catch an eddy at the bottom since BZ Falls is coming up soon. There is one rapid in between The Flume and BZ Falls.
Mile 5: BZ Falls is a steep drop that should be scouted and can be portaged on the right. This is the most commonly portaged rapid on the Truss.
Mile 5.3: Take-out at Maytag (III) or continue down the middle section of the White Salmon.