Cal. Code of Civil Procedure § 1240.670

(a) Subject to Section 1240.690, notwithstanding any other provision of law, property is presumed to have been appropriated for the best and most necessary public use if all of the following are established: (1) The property is owned by a nonprofit organization contributions to which are deductible for state and federal income tax purposes under the laws of this state and of the United States and having the primary purpose of preserving areas in their natural condition. (2) The property is open to the public subject to reasonable restrictions and is appropriated, and used exclusively, for the preservation of native plants or native animals including, but not limited to, mammals, birds, and marine life, or biotic communities, or geological or geographical formations of scientific or educational interest. (3) The property is irrevocably dedicated to such uses so that, upon liquidation, dissolution, or abandonment of or by the owner, such property will be distributed only to a fund, foundation, or corporation whose property is likewise irrevocably dedicated to such uses, or to a governmental agency holding land for such uses. (b) The presumption established by this section is a presumption affecting the burden of proof.