A delightful and scenic trail leads down from the southwest side of Deception Pass Bridge [1] to a rocky beach strewn with bleached driftwood.
A 15-minute hike to the highest point on the island, 400-foot Goose Rock, provides views of the San Juan Islands [2], Mt. Baker [3], Victoria, and Fidalgo Island, and possibly bald eagles soaring overhead. The trail starts at the south end of the bridge, heading east from either side of the highway; take the wide trail as it follows the pass, then take one of the unmarked spur trails uphill to the top. A half-mile hiking trail circles Rosario Head, the wooded point of land that juts into Rosario Bay (technically part of the 75-acre Sharpe County Park). The shoreline is a fine place to explore tidepools.
Other hiking trails lead throughout Deception Pass State Park [4], ranging from short nature paths to unimproved trails for experienced hikers only.
Links:
[1] http://www.moon.com/destinations/washington/north-puget-sound/whidbey-island/deception-pass-state-park/sights
[2] http://www.moon.com/destinations/washington/san-juan-islands
[3] http://www.moon.com/destinations/washington/north-cascades/mount-baker
[4] http://www.moon.com/destinations/washington/north-puget-sound/whidbey-island/deception-pass-state-park