(a) Following issuance of the regulations in this part, Shasta County shall submit to the Secretary for his approval, all zoning ordinances and amendments thereto duly adopted by the county which are in force and applicable to property within the Whiskeytown Unit and which demonstrate conformity with the standards contained in the regulations in this part. This shall include any ordinances and amendments in effect prior to the issuance of the regulations in this part which demonstrate such conformity and any that have been adopted specifically to implement the regulations in this part.

(b) Any new uses, and the location, design and scope of any new developments, permitted under the regulations in this part shall be harmonized with adjacent uses, developments and the natural features and shall be consistent with the current Master Plan proposed or adopted by the National Park Service for the Whiskeytown Unit, so as to minimize disruption of the natural scene and to further the public recreational purposes of the aforesaid establishment act for this unit.

(c) Zoning ordinances for the districts hereinafter prescribed shall conform to the general and specific standards contained in the regulations in this part to assure that use and development of the lands within the Whiskeytown Unit are consistent with the objectives of the Congress to protect and preserve the values of the lands in such unit for public use and enjoyment, as set out in the Act of November 8, 1965 (79 Stat. 1295). Except as otherwise provided herein, no additional or increased commercial or industrial uses are permitted within these districts. Any existing nonconforming commercial or industrial uses shall be discontinued within 10 years from the date of this section: Provided, however, That with the approval of the Secretary such 10-year period may be extended by the county for an additional period of time sufficient to allow the owner a reasonable opportunity to amortize investments made in the property before November 8, 1965.