FROM THE SOUTH
Use US Highway 101.
Fortuna is approximately 250 miles from San Francisco, about a 4.5 hour pleasant drive through wine and redwood country.
There is a very nice scenic alternate route worth taking called The Avenue of the Giants. Its length is a little over 30 miles and parallels Highway 101 between Garberville and Scotia (download the map). The avenue offers the most beautiful display of old growth redwoods and there are convenient services available along the way. Take time to picnic, hike, swim or even enjoy a bike ride in the cool calm of the ancient redwood forests.
FROM THE NORTH
Use Interstate 5 and US Highway 101.
Fortuna is approximately 429 miles from Portland, about a 7.5 hour drive along the beautiful Oregon coast and the striking Cascade Range.
From Portland take Interstate 5 south to Grants Pass. Turn west onto US Highway 199 and connect to Highway 101 at Crescent City. Travel south on Highway 101 to Fortuna. As an alternate route, take Interstate 5 south all the way to Redding and there turn west onto State Highway 299 to Arcata, where you connect and turn south on Highway 101.