Opposite the urban area of Seattle, across the wide bay of the Puget Sound, lies the Olympic mountain range. Here, in the northwestern coastal region of the United States, Sitka spruce thrives besides Western hemlock, Douglas-fir and various species of the genus Thuja. The Western red cedar, when found in its natural range, often produces offshoots from the base of the trunk that can, in turn, grow into mature trees. Along the edges of meadows grows the Vine maple, a rather exceptional shrub-like species among the maples that shows more affinity with smaller Japanese maple species than with American or European ones. This group increased in size when the arboretum expanded over the Kapucijnendreef in the 1950s and later. Near the pond named Barakkevijver a rejuvenated riverine forest has been recently created with Oregon ash, Red alder and Balsam poplar.