California Code, Public Resources Code - PRC § 5032

(a) “Qualified historical property” pursuant to Section 5031 includes:

(b) “Qualified historical property” does not include individual sites without structures.

(c) Commercial operation in itself does not necessarily disqualify a landmark's registration. However, should a commercial enterprise by its physical development plans, or its proximity, impact, excessive use, or management philosophy so dilute or erode the significance of or quality of the landmark's integrity, then an adverse effect shall have occurred and its registration may be withdrawn.