As branches historically were the first markings used, these on-snow routes are called kvisteruter, literally "branch-marked routes" in Norwegian.
Winter waymarking is done for the principal skiing season at Easter, although some routes are waymarked as early as February. In all, each year, some 6,500 km of skiing tracks are waymarked.
Download map showing waymarked ski routes winter here
For live updates of prepared ski trails, see skisporet.no