N.J. Stat. Ann. § 40:37-255

The board of chosen freeholders before proceeding to acquire by purchase or condemnation lands contiguous to any such public park or recreation ground shall first determine the quantity of land to be acquired and shall cause a survey and map to be made thereof embracing the park or recreation ground which the lands so to be acquired adjoin, as well as the land to be acquired, which survey and map shall be a public record and kept in the office of the clerk of the board of chosen freeholders.