Geology of the Pacific Northwest along their course. The larger cataract was that of the upper Grand Coulee, where the river roared over an waterfall. The eroding power of the water plucked pieces of basalt from the precipice, causing the falls to retreat and self-destruct by cutting through to the Columbia River valley near what is now the Grand Coulee Dam. The other major cataract is now known as Dry Falls. It started near Soap Lake in Washington State, where less resistant basalt layers gave way before the great erosive power of this tremendous torrent and waterfalls developed. As in the upper Grand Coulee, the
Grand River (Michigan) stampede, as millions of logs flowed uncontrolled down the river and became trapped in bends or against bridges. The result was a logjam of incredible proportions that clogged the river for 47 miles (10 million Feet of logs trapped in Lowell, 95 million Feet of logs trapped in the "Big Bend" northeast of Grand Rapids, 80 million Feet of logs trapped in Ottawa County). Grand River Avenue (or Grand River Road) was built early in the settlement of Michigan and runs from the head of navigation on the Grand to downtown Detroit. It formed an important part of an early