 They often have a visual height (height above nearby crestlines) of one mile or more.The highest peaks, such as the Mount Rainier, dominate their surroundings for .The northern part of the range, north of Mount Rainier, is known as the North Cascades in the United States but is formally named the Cascade Mountains north of the Canada–United States border, reaching to the northern extremity of the Cascades at Lytton Mountain.