S.D. Codified Laws § 43-13-20.5

No wind or solar developer may require a property owner to maintain the confidentiality of any negotiations or terms of any proposed easement or lease except that the parties may agree to a mutual confidentiality agreement in the final executed wind or solar easement, wind or solar lease, or a separate document. Any disclosure of trade secrets or competitive business plans of the developer may be subject to the confidentiality agreement whether occurring before or after execution of the wind or solar easement or wind or solar lease.