Abstract: A picket fence structure comprising a plurality of coplanar contiguous vertical pickets which have at least one key slot cut into each edge, so that the mating edges of two adjacent pickets have their key slots in the same position. A key is placed in each key slot, which serves to keep the pickets in a planar assembly. There are preferably two key slots, one near each end, on each edge of the pickets. The planar assembly of pickets, held together by suitable keys in the key slots, are keyed to fence posts contiguous with the outermost pickets. The keying of the outermost pickets to adjacent fence posts, can be by longitudinal grooves or slots in the faces of the fence posts, or by means of key slots similar to those which hold the individual pickets into a planar assembly. The keys may be rods or dowels. They are preferably discs of a diameter that will fit into semi-circular key slots in the matching edges of the pickets.