You took the North Coast Route (via Matane)?
The campground is on road 132 (boulevard Griffon) at the entrance of the village of Anse-au-Griffon. Past Rivière-au-Renard. In Rivière-au-Renard, be careful of turning left to follow the 132. If you simply follow the road, it becomes the 197.
South side (via Percé)?
After you go through Forillon National park, as well as the villages of Cap-des-Rosiers and Anse-au-Griffon, you will find the campground on road 132 (boulevard Griffon), 3 km from the heart of Anse-au-Griffon (where the harbour is located). Look to your right.