Before the department makes any finding of the existence of an imperative and unavoidable public necessity of a higher nature, or grants any estate, interest, or right in a nature preserve, or disposes of a nature preserve or of any estate, interest, or right therein as provided in section 55-11-11, or enters into any amendment of any articles of dedication as provided in section 55-11-06, it shall give notice of such proposed action and an opportunity for any person to be heard. Such notice must be published once each week for two successive weeks in a newspaper having a general circulation in the county or counties wherein the nature preserve is     located and must be mailed within five days after such publication to all persons who have requested notice of all such proposed actions. The notice must set forth the substance of the proposed action and describe, with or without legal description, the nature preserve affected, and must specify a place and time not less than thirty days nor more than sixty days after such publication for a public hearing before the department on such proposed action. All persons desiring to be heard must have a reasonable opportunity to be heard prior to action by the department on such proposal.