On the smooth rock shelves of the Whiteshell there are strange figures made of boulders. They are found usually on high plateaus, or on the crest of precipitous portages. Mystery surrounds these figures. No one knows who built them, or how they were used. Some guesses have been made. Some opinions have been expressed, but no appraisal has satisfied all authorities. Such opinions as have been voiced fall far short of unanimity. This unhappy void probably springs from the fact that no archaeologist or anthropologist has ever made a definitive study of these stones, which are commonly referred to as boulder mosaics.
Some of the stones that form the mosaics weigh several hundred pounds. These may rest upon the very places where they were cast by the receding ice shield. Smaller stones have been placed in line with larger ones, and some surround large central boulders to form a variety of patterns. The designs include, squares and triangles, circles and spoked wheels. Some outline the figures of men, turtles and fish, others form snakes and birds. Most of the rocks are heavily encrusted with moss and lichens. Some are completely covered, and only after painstaking search may they be distinguished from the underlying terrain.
Some of the largest mosaics are snakes. Their long sinuous coils stretch for 300 feet or more across the base rock. The head is usually a large, flat rock, triangular in shape. Stones of diminishing size taper off toward the tail. The figures of fish and men are sometimes as long as 90 feet, and frequently as broad as 20 feet at the widest point. Each turtle covers an area about eight times the size of a common school desk. Some designs of birds are as large as a standard basketball floor.
One series of mosaics, situated on a large plateau, forty feet above the surrounding muskeg, contains nothing but geometric designs. There are triangles enclosed in circles and small circles within larger ones. There are squares and rectangles and some parallelograms. Some of these are linked by long chains of smaller stones whose convex loops always incline to the perimeter.