Much more efficient to go via the sea. They could tap the rivers all up the Oregon and Washington coast line or as this paper looks at go all the way to Alaska or B.C.
https://www.princeton.edu/~ota/disk1/1992/9203/9203.PDF
That is a very interesting concept, but as noted in the paper the expense would likely be prohibitive. I think it is great that you and others are trying to come up with innovative solutions. You do realize however that your dreams are completely in vain?
The real problem is that despite having the most natural resources of any state, abundant beauty, and almost unimaginable wealth... California is well on the way to 3rd world hell hole status. Their socialist leaning society is leading the country in leftist decadence. People are fleeing the state to get away from high taxes and a government bureaucracy that is completely out of control. California’s ability to successfully complete any massive government project will continue to wane in the future.
The Southern half of the state is rapidly becoming North Mexico and I do not see the trend reversing in my lifetime. We have family in California and had planned to retire there. We are still tempted because of the wonderful climate and terrain, but realistically it is a bad place to move on a fixed income.