For the purpose of perpetuating every survey, the surveyor shall establish his or her corners by taking bearings on trees and noting particularly their course and distance from the corner. When there are no trees within a reasonable distance, he or she shall perpetuate his or her corners by erecting mounds of turf at least two and one-half feet (2½') at the base and two feet (2') high. In lieu of mounds, stones may be planted in the ground to a depth not less than twelve inches (12"), which shall not be less than eighteen inches (18") long, eight inches (8") wide, and three inches (3") thick. The stones shall be described in the field book.