The easiest thing to do is enter 223 Battery Way, Port Townsend, WA 98368 into Google Maps for exact directions from your location.

Via Car from SeaTac Airport

Non-Ferry Route:
From SeaTac airport, you can drive south, via I-5 S to Tacoma, and WA-16 W and WA-3 N to WA-104 W. This route takes approximately 2 hours, 10 minutes at best, and can be congested during rush hours.

Ferry Routes via Car:
From SeaTac, drive to the Downtown Seattle Ferry Terminal (Colman Dock) or the Edmonds Ferry Terminal. Ferries to Bainbridge Island, Kingston, or from Victoria B.C. and Whidbey Island will get you to the Olympic Peninsula.

• From Victoria, British Columbia via Victoria/Port Angeles Ferry:
  Take the Victoria-Port Angeles ferry (90-minute crossing). Ferry exits onto Laurel St .2 miles. Turn left onto E. Railroad St. 0.1 miles, take 1st right onto N. Lincoln St./US 101 E. and continue for 34.2 miles. Turn left onto WA-20, go 7.8 miles and turn left to stay on WA-20 for another three miles and you have reached Port Townsend.
• From Vancouver, B.C. via Whidbey Island – Port Townsend Ferry
  Follow Provincial Route 99 south to border crossing. Provincial Route 99 S. becomes I-5 S. Go 46.1 miles take exit 230 toward WA-20/Burlington/Anacortes. Go .4 miles turn right onto WA-20 E. make a U-turn onto WA-20 W. Go 11.8 miles turn left onto WA-20 and continue 16.4 miles turn right to stay on WA-20, go 9.5 miles turn right onto S. Main St. go 0.6 miles (S. Main St. becomes Engle Rd.), go 3.3 miles. Take the Port Townsend-Keystone Ferry. You are now in downtown Port Townsend.

NOTE: Ferry reservations are encouraged – and in some high-season periods – required for the Port Townsend/Whidbey Island ferry.

FERRY SCHEDULES (link to current schedule)

• Seattle / Bainbridge Island
• Edmonds / Kingston
• Whidbey Island / Port Townsend
• Victoria, BC / Port Angeles

Monday through Friday, you can take advantage of two great commuter services to get to/from Port Townsend from Seattle:

• From Downtown Seattle, you can take the Kitsap Fast Ferry to Kingston, and from Kingston there is a once-daily express bus to Port Townsend, the #14 Kingston Express. Please check schedules carefully, the hours are very limited. Visit Jefferson Transit for more information on these options.
• In addition to the above express routes, you can transfer via the regular bus systems to/from Bainbridge Island or Kingston Ferry Terminals. Consult Jefferson Transit and Kitsap Transit for options on these.
• To travel by bus to Fort Worden from Four Corners or Haines Place drop off points, consult the busline for #2, the Fort Worden Loop

GREYHOUND/DUNGENESS SEATAC to PORT TOWNSEND SERVICE
This is a great option if you can time it with your arrival at SeaTac. $42 one way. Book tickets in advance. 

PRIVATE SHUTTLE – ROCKET TRANSPORTATION
Rocket can arrange door-to-door pickup/drop off to SeaTac from the peninsula. By advance reservation only. Rates start at $75 for a one-way trip from SeaTac to Port Townsend. 

Jefferson Transit operates municipal bus service (Bus Line #2) to Fort Worden daily at two-minutes past the hour, departing from The Food Co-op in downtown Port Townsend (at the intersection of SIMS WAY, WATER STREET and KEARNEY STREET in Port Townsend.)  

There is no public bus service on Sundays. Route maps and current schedules available online. The fare is free.

Peninsula Taxi operates service in Port Townsend.  They are located at 928 Tyler Street, Port Townsend. (360) 385-1872

Welcome to Fort Worden "an iconic and cherished state park and lifelong learning center". Find campus maps here

"Fort Worden’s magnificent setting encompasses 434 acres with 12 miles of forested hiking trails, two miles of walkable saltwater beaches and commanding views of the Olympic and Cascade mountains as well as views across the Strait of Juan De Fuca to the San Juan Islands. The Fort features 73 historic buildings with four museums and creative spaces for art and educational programs, yoga, woodworking and more."
source: https://fortworden.org/