.. if I were to do the Portland coast which is the best section? Vancouver then south to Portland? Or start in Portland then south?
Geography:
South of Portland is the Willamette river valley, 'I-5 corridor' not the Seacoast..
the City is built where that river flowing north, joins the Columbia, It flows north, then west,
to the Sea.
& there is the other Washington state Vancouver that is across the Columbia from Portland Oregon.
a Coastal Mountain range separates the Willamette River valley, from the Seacoast.