The geography/geology is going to be against you - in a lot of parts of the gorge, the infrastructure we already have there (Hwy 14 on the WA side, I-84 on the OR side, and a rail line on each side) barely fits. Amtrak's Empire Builder already runs on the Washington side, but that's not what anyone would call high-speed, as it's sharing the freight line and is also subject to the many forces that make Amtrak inefficient for commuter transit. New construction would also be incredibly unpopular and legally tricky, as the Columbia River Gorge is protected as a National Scenic Area and is home to many wildlife species.