The Guo-Kang fossil bed contains fossils of shellfish formed about 1 to 6 million years ago. The rock layers contain bivalve, pteropod, gastropod, and coral fossils. In 1930, the Governor-General of Taiwan had already designated this fossil bed for preservation. In 1955, the Miaoli County Literature Committee erected a stele to commemorate the Guo-Kang fossil bed. An announcement was made that this site was for academic research only and was not to be recklessly cultivated, in order to preserve this ancient fossil bed.