A new 2.5-mile segment of the San Francisco Bay Trail will open to the public Sunday afternoon along the edge of the tidal wetlands at Sears Point.

The trail, part of Sonoma Land Trust’s Sears Point Wetland Restoration Project, will allow visitors to observe the growth of a marsh in the wake of last fall’s breaching of a levee that allowed tides to return to 1,000 acres of land diked in the late 1800s.

Linked to an existing 1.5-mile trail that starts at Port Sonoma, the 4-mile walkway is part of a planned 500-mile path around San Francisco Bay, the Land Trust said.

The new trail will open with a ribbon-cutting ceremony at 2:30 p.m., followed by an official first hike led by Doug McConnell of NBC’s “Open Road” program.

The event is free and attendees are asked to register online at sonomalandtrust.org. Organic ice cream will be available for free as long as supplies last.

Starting May 21, the Land Trust will offer a docent program, with interpretive talks and bird walks, at the trail from 9 a.m. to noon every Saturday.

The trail entrance is on Reclamation Road, south of the Highway 37/Lakeville Highway intersection.