California Code, Government Code - GOV § 66452.27

(a) A legislative body located within the County of Butte, may extend the expiration date for up to 36 months of any tentative map, vesting tentative map, or parcel map for which a tentative map or vesting tentative map, as the case may be, was approved on or after January 1, 2006, and not later than March 31, 2019, that relates to the construction of single or multifamily housing, and that has not expired on or before the effective date of the act that added this section.

(b) Any legislative, administrative, or other approval by any state agency that pertains to a development project included in a map that is extended pursuant to subdivision (a) shall be extended by 36 months if the approval has not expired on or before the effective date of the act that added this section.

(c) The extension provided by subdivisions (a) and (b) shall be in addition to any extension of the expiration date provided for in Section 66452.6, 66452.21, 66452.22, 66452.23, 66452.24, or 66463.5.