Statewide extents of wilderness are mapped and calculated for four historic time-slices that reflect major periods of national park development in Tasmania. The representation of wilderness in the Tasmanian reserve system is calculated for 1937, 1970 and 1992. National parks were established in wilderness areas during all major periods of reserve development. While the total core wilderness area in Tasmania decreased by 63% between 1916 and 1992, the core wilderness area captured in the reserve system increased by 618%, with the largest increase being in the post-1970 period. However, those parks established prior to 1970 suffered an enormous attrition of their wilderness resource. This reflects man-agement policies inconsistent with the maintenance of wilderness during early periods of national park development. The huge increase in wilderness area captured in the reserve system after 1970 suggests that wilderness conservation only became a significant motive behind the expansion of the reserve system in the later decades of the twentieth century.