C.R.S. § 36-20-123

(1) The mere dissemination of materials and substances into the atmosphere pursuant to an authorized project shall not give rise to the contention or concept that such use of the atmosphere constitutes trespass or involves an actionable or enjoinable public or private nuisance. (2) Intentionally left blank —Ed. (a) Failure to obtain a permit before conducting an operation, or any actions which knowingly constitute a violation of the conditions of a permit, shall constitute negligence per se. (b) The director may order any person who is found to be conducting a weather modification operation without a permit to cease and desist from said operation. Any person who fails to obey said order commits a class 6 felony and shall be punished as provided in section 18-1.3-401 , C.R.S.