After taking a left at the trail split, continue on the path into the marshland area. You'll cross a long wooden bridge, past a red house (used as a picnic area) and over Newark Slough.
At the end of the footbridge, you'll hit a T and can go left or right. The Tidelands Trail continues to the left.
To the right is part of the Newark Slough Trail -- a levee construction around the salt ponds. It's closed until 2010 for levee maintenance. Read about Cargill's Mallard II -- the equipment used to dredge during this project.