Why did Industry expand across the bay to Oakland, Pittsburgh and Contra Costa county rather than further south toward San Mateo in the 19th and early 20th centuries?

Because the wealthy estates owners made land too expensive

Explanation:

In recent time, the development of industries in the south toward San Mateo as slowed down due to the fact that the estates owners in the south have made land too expensive for the industrialist to acquired. The tends development to drift toward other part of nation towards Oakland, Pittsburgh and Contra Costa.