Actually, west of the mississippi (and assuming all of Louisiana and Minnesota) the population is only about 130 million - so those three states are about 40% of that population. Given the rapid growth of texas, colorado and arizona, and Nevada (well Las Vegas) in the last 15 years, it wouldn't surprise me if those three states would have been over half the population west of the Mississippi not that long ago.
As for within 5 Miles of I-5.. probably not, but within it's area of influence, for sure - the western parts of those three states are pretty empty, even by my midwest trained standards.
As for within 5 Miles of I-5.. probably not, but within it's area of influence, for sure - the western parts of those three states are pretty empty, even by my midwest trained standards.