They don't need this along Cascadia. All of the major population centers are 60 miles inland (in between the coastal and cascade mountain ranges). There are jus

They don't need this along Cascadia. All of the major population centers are 60 miles inland (in between the coastal and cascade mountain ranges). There are just very small town on the coasts and the coastal mountain range rises very quickly from the coast. You can get to high ground from just about anywhere on the coast fairly quickly.