The valleys are quite low, resulting in great local relief, and major passes are only about 1,000 m (3,300 ft) high. It is extremely rugged, with many of the lesser peaks steep and glaciated. The northern part of the range, north of Mount Rainier, is known as the North Cascades. The tallest peaks, such as the 14,411 foot (4,392 m) high Mount Rainier, dominate their surroundings for 50 to 100 miles (80 to 160 km). They often have a visual height (above nearby crestlines) of one mile (1.6 km) or more. The tallest volcanoes of the Cascades are called the High Cascades and dominate their surroundings, often standing twice the height of the nearby mountains. It is 80 miles (130 km) wide in northern Washington, while at its northern apex at Lytton Mountain (2,049 m) in Canada, near the confluence of the Fraser and Thompson Rivers, the range is only 10 miles (16 km) wide. The southern end of the Cascade Range is about 30 to 50 miles (50 to 80 km) wide and 4,500 to 5,000 feet (1,370 to 1,520 m) high. Its approximate 700 mile (1,127 km) length is home to a great diversity of plant and animal life, as well as to majestic mountain scenery. The Range has had a major influence on the climate, agriculture, economics, population spread, and settlement patterns of the Northwestern United States and the Pacific Northwest region of North America, and have been a major facet of life for generations of Native Americans. Geological Survey, minor eruptions of Mount Saint Helens have also occurred, most recently in 2006. According to monitoring systems of the U.S. The two most recent were Lassen Peak in 1914 through 1921 and a major eruption of Mount Saint Helens in 1980. All of the known historic eruptions in the contiguous United States have been from Cascade volcanoes. The Cascades are part of the Pacific Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. The small part of the range in British Columbia is called the Canadian Cascades or Cascade Mountains the latter term is also sometimes used by Washington residents to refer to the Washington section of the Cascades in addition to North Cascades, the more usual American term, as in North Cascades National Park. It includes both non-volcanic mountains, including the rugged spires of the North Cascades, and the notable volcanoes known as the High Cascades. states of Washington and Oregon to Northern California. The Cascade Range is a major mountain range of western North America, extending from Canada's British Columbia through the U.S.