Coste Rocks Park was designated as a class A provincial park on May 20, 2004 following recommendations from the Kalum Land and Resource Management Plan.
Coste Rocks consists of three small, rocky islets and a nearby reef off the south end of Coste Island. The rocks are the top of an underwater pillar that has vertical faces to a depth of 45 metres. The vertical walls of the pillar result in vertical zonation of marine life and are known locally as an excellent underwater sea garden wall. Coste Rocks is a popular scuba diving location and tidal waters sport fishing spot. There are no trees or facilities in the park and hunting is not allowed.
The rocks are also a popular haul-out spot for harbour seals which can often be seen on the northeast rocks.