The San Juan Islands is a 57.9 mile point-to-point trail located near Friday Harbor, WA and is rated as moderate. The trail is primarily used for road biking and is accessible year-round.
Recently took the ferry to Friday Harbor. I'd suggest parking and walking on then pay 15.00 for a day bus pass on the Isle. No car needed to see it all. Save exploring Friday Harbor for the end of the day. The bus took me to Roche Harbor first. Walk to the mausoleum from here. it's not an overly thrilling hike, but the reward at the end is worth it. Take the next shuttle to English Camp and do some more hiking. When i was there, there was an active osprey nest you could watch. From there take the next shuttle to lime kiln park. This is where you watch the orcas from land. the trail hugs the coast and there is a great little lighthouse for pictures. The bus takes you back to Friday Harbor where you can walk the town and harbor with time to eat before catching the ferry back to the mainland. excellent day trip if you manage your time right.
Love this little seaside town-- bustling in summer. Sleepy in the winter. Great restaurants, great activities.