Water, Water Everywhere The Ottawa River from the Deschênes Rapids to the Chaudières Rapids is a combination of slow- and fast-moving water. The rock you are standing on was formed by the lithification of sediment deposited in a warm tropical ocean that once covered this area 450 million years ago. Look closely, and in a few places you can see rounded domes in the rock called stromatolites — the algae and bacteria that built these domes are believed to have produced the Earth’s oxygen. The topography of this section of the river appears much the same today as it has since the retreat of the Champlain Sea after the last ice age, just 8,000 years ago. Most of the pine that used to grow along the banks has been replaced by young mixed woods consisting of red and bur oak, basswood, elm, white and black ash, silver maple, willow and poplar. Over 200 species of birds can be seen annually, ranging from waterfowl and shore birds to songbirds. At least 15 species of fish exist in this section of the river, and in recent years several thousand brown trout have been stocked annually.     Life at the Rapids The First Nations people once lived, hunted and fished along the banks of the Ottawa River. Archaeological evidence establishes their presence in the valley approximately three to four thousand years ago. European settlers and fur traders settled here, too. It is still possible to walk in the voyageurs’ footsteps on their old portage path at Brebeuf Park on the Quebec shore of the Lemieux Rapids. The first lumber mill on the Ottawa River was built by Philemon Wright circa 1800. Approximately 120 metres east of this kiosk, the ruins of the first steam-driven mill, erected in the 1870s, are still visible. Today, the river still sustains the people living in the region. Over a million people get their drinking water from three filtration plants located along the river. It has also become significant for its many recreational opportunities. The National Capital Commission maintains parkland and pathways in the region that allow residents and visitors to enjoy walking, cycling, swimming, paddling, fly-fishing and bird watching.