ecosystem of the park and the rock. Description Percé Rock is a massive siliceous limestone stack formation, with sandstone and siltstone veins, with steep rock faces on all sides. It is long, wide, and high at its highest point. It is described as a narrow bluff emerging out of the sea, "resembling a beached supertanker from some angles". For four hours at a time during low tide, the water recedes from a wide spit that allows the rock itself to be visited. History Percé Rock's huge limestone formation is geologically dated to the Devonian period of more than 400 million years ago (375 million years is also mentioned). However, Percé Rock is only a small component of the large areas of Devonian rocks that occupy the interior that were first mapped in 1844 by Sir William Edmond Logan, known as the father of Canadian geology. Fossils in such rocks show a variety of animal and plant communities from both terrestrial and marine habitats from the Devonian period. The Percé Rock contains 150 species of different fossils such as brachiopod, trilobites, dalmanites, corals and marine worms from the Devonian period. Originally, the Percé Rock was inferred as connected to the main land. When Jacques Cartier, the first colonist arrived here in 1534, he reported three arches in the massive rock formation. In time, two of the arches disappeared, with the last one collapsing on June 17, 1845, leaving a separated pillar. When it was seen in 1603 by the French geographer and founder of Quebec City, Samuel de Champlain, it had only one arch. However, in 1760, a picture of Percé Rock drawn by an English officer, Captain Hervey Smyth, showed two arches, one of which collapsed in June 1845. Percé rock's two large holes were cut through by the sea waves. One of the holes seen now is an arch described as "gothic arch of rock", which is about high. A small boat can pass through the arch during high tide. Of the two arches, the outer arch, which collapsed with great force in 1845, remains in the form of an "obelisk". In early 1900s, enchanted by the beauty of the Percé Rock, travellers started visiting the area of Gaspe, Percé and Bonaventure Island. In popular culture Percé Rock is a major tourist attraction in Quebec, with picturesque views of the rock from both Percé and nearby Bonaventure Island. French