Start with a hearty breakfast in San Diego before heading to the airport; choose The Mission for a reliable Latin-inspired morning or a cafe near SAN if you're short on time.
Drive/taxi to San Diego International (allow 90–120 minutes to check in) and take a mid-morning flight to San Francisco to maximize sightseeing time — flight ~1h30m.
Take the 2–3 hour Alcatraz tour to tour the former prison and hear the guided audio; tours run multiple times daily but sell out — reserve timed tickets ahead.
If you have energy, walk the Embarcadero for night views of the Bay Bridge or drive to Coit Tower for city lights (Coit Tower hours vary; night views often accessible nearby).
Walk among coastal redwoods in Muir Woods — timed-entry reservations and parking slots are required; typical visiting hours are ~8:00am–6:00pm but confirm when booking.
Begin the scenic inland drive north on US-101 toward Garberville/Weott (Avenue of the Giants). Expect ~4.5–5.5 hours of driving depending on stops; pack water and allow time for short photo breaks.
Arrive in the Humboldt Redwoods region and check into a local lodge or B&B; enjoy a relaxed dinner at a nearby restaurant and rest for a full day among giants tomorrow.
Drive the scenic Avenue of the Giants and hike the Founders Grove Boardwalk to see ancient coastal redwoods; these areas are open daylight hours and offer easy, interpretive trails.
Continue along the park’s scenic roads with stops for photos and short walks — routes are typically open from dawn to dusk; check road conditions if wet.
Drive north to Prairie Creek/Jedediah Smith areas and hike the Lady Bird Johnson Grove trail to experience large old-growth redwoods; trails are open sunrise to sunset — check park alerts for closures.
If driving a suitable vehicle, take Howland Hill Road (dirt) or other scenic loops to see more remote groves and quiet forest sections; drive times vary, and roads may close in poor weather.
Overnight in Crescent City or head to Arcata (ACV) for a next-day flight back to San Diego/SFO; ACV has limited flights — if flying same evening expect limited schedules and possible connections via SFO.