Cal. Rev. & Tax. Code § 3791
Whenever property tax defaulted for five years or more, or three years or more in the case of nonresidential commercial property, as defined in Section 3691, in an applicable county, has been sold for taxes for two or more years or has been deeded for taxes to a taxing agency other than the state, the governing body of the taxing agency may, as provided in this article, make an agreement with the board of supervisors of the county in which the property is situated for the purchase of, or for an option to purchase, all or any of the tax-defaulted property or any part thereof including a right-of-way or other easement. When a part of a tax-defaulted parcel is sold the balance continues subject to redemption, if the right of redemption has not been terminated, and shall be separately valued for the purpose of redemption in the manner provided by Chapter 2 (commencing with Section 4131) of Part 7 of this division, except that no application need be made.
Ca. Rev. and Tax. Code § 3791