“Should the West Coast secede, there would likely be an armed revolt in northeastern California by those seeking to create a new state called Jefferson. The State of Jefferson movement has been around for decades.”
I do not think Jefferson would have any ports even close to what San Francisco, LA and San Diego have. Maybe I’m wrong about that and they could be developed along with rail access to them. But that’s the problem.
I don't think San Francisco is even used as a port anymore.
If the state of Jefferson gets coastal access by acquiring Del Norte and/or Mendocino Counties, Eureka and Crescent City could be developed into ports. But even so, landlocked states like Nevada, Colorado, Utah and Idaho have done fine without access to the sea.