Coast Mountains

These are big mountains by the sea.

They sit in North America. They go from Yukon down to the Fraser River. The mountains are near the Pacific Ocean.

It rains a lot on one side. This rain helps green forests grow.

The other side is much drier. Some parts have huge fields of ice. These ice fields help feed big rivers.

Many of these mountains are very tall. Mount Waddington is the highest one. It is a grand place to see.

The Coast Mountains are a large mountain range. They sit in western North America. They stretch from the Yukon down to the Fraser River. They are near the Pacific Ocean.

The mountains have three main parts. These are the Pacific Ranges, the Kitimat Ranges, and the Boundary Ranges. The Boundary Ranges are the largest part. They go from the Nass River to the Kelsall River. This part has large icefields. One is the Juneau Icefield.

The weather here changes based on where you stand. The ocean air brings much rain to the west side. This rain makes thick, green rainforests. The mountains also have huge fields of ice. These icefields help feed many big rivers.

The east side of the range is much drier. It is less steep than the west. Mount Waddington is the highest peak. It is in the Pacific Ranges. Most of the land here is wild and empty. Only a few places have people or big ski resorts.

The Coast Mountains are a huge mountain range in western North America. They sit right next to the Pacific Ocean. The range stretches from the Yukon all the way down to the Fraser River. This includes parts of the Alaska Panhandle and most of the coast of British Columbia. They are part of a very large system called the Pacific Coast Ranges. This system forms a long backbone along the western side of North America, Central America, South America, and Antarctica. Because they are so close to the sea, they are often called the Coast Range.

This mountain range has three main parts. The first is the Pacific Ranges, which are the southernmost part. They reach from the Fraser River to Bella Coola. This area holds four of the five major coastal icecaps in the south. These icecaps are the largest of their kind in temperate areas of the world. They help feed many important rivers. The middle part is called the Kitimat Ranges. It goes from the Bella Coola River to the Nass River. The third part is the Boundary Ranges. These are the largest subdivision and stretch from the Nass River to the Kelsall River.

The mountains change the weather for the land around them. The mountains sit just east of the Pacific Ocean. When moist air from the ocean hits the mountains, it is forced to rise. This causes very heavy rainfall on the western slopes. This rain helps create lush, green temperate rainforests.

On the eastern side, the mountains are different. The land is less steep and much drier there. These mountains protect the British Columbia Interior from the wet ocean weather. This makes the summers warm and the winters cold and dry.

Long ago, the mountains were built by many different events. About 130 million years ago, volcanic islands called the Insular Islands moved toward North America. They traveled on a tectonic plate. Eventually, these islands crashed into the edge of the continent. This collision crushed and folded the rocks.

Huge amounts of molten granite pushed into the old rocks. This created the largest granite outcropping in North America. Later, about 100 million years ago, new volcanoes grew along the coast. Many of these volcanoes have since disappeared due to erosion.

Today, the Coast Mountains are mostly wild and empty. Most of the land is undeveloped. There is some logging and a large ski resort in Whistler.

You can find many high peaks here. Mount Waddington is the highest mountain in the range. It is also the highest mountain located entirely within British Columbia. It sits in the Waddington Range. The mountains are part of the Pacific Ring of Fire. This is a ring of volcanoes and mountains around the Pacific Ocean.

The Coast Mountains are a massive mountain range located in the Pacific Coast Ranges of western North America. This range stretches from the southwestern Yukon, through the Alaska Panhandle, and along nearly the entire coast of British Columbia down to the Fraser River. Because of their proximity to the sea, they are often called the Coast Range. They are part of the larger Pacific Mountain System. This system includes the Cascade Range, the Olympic Mountains, and the California Coast Ranges. On a global scale, the Coast Mountains are part of the American Cordillera. This is an extensive chain of mountain ranges that forms the western backbone of North America, Central America, South America, and Antarctica.

The range is divided into three distinct geographic subdivisions. The first is the Pacific Ranges, which are the southernmost section. They extend from the lower reaches of the Fraser River to Bella Coola. This area contains four of the five major coastal icecaps found in the southern Coast Mountains. These icecaps are the largest temperate-latitude icecaps in the world and provide water for many major rivers. The second subdivision is the Kitimat Ranges. This central section extends from the Bella Coola River and Burke Channel in the south to the Nass River in the north.

The third and northernmost subdivision is the Boundary Ranges. This is the largest subdivision of the entire range. It spans the border between British Columbia and Alaska and reaches into the Yukon. The Boundary Ranges include the Juneau Icefield and the Stikine Icecap.

The geography of the Coast Mountains creates a dramatic difference in local weather. Because the mountains sit just east of the Pacific Ocean, they act as a barrier for moisture-laden air. As this air hits the mountains, it is forced to rise. This process causes heavy rainfall on the western slopes. This precipitation is among the heaviest in North America and supports lush, dense temperate rainforests.

In contrast, the eastern flanks of the range are much drier. The mountains protect the British Columbia Interior from Pacific weather systems. This results in a landscape with less steep terrain and a climate with dry, warm summers and dry, cold winters. Beyond these slopes lies the Interior Plateau.

The geological history of the range is a complex story of moving tectonic plates. About 130 million years ago, a group of volcanic islands known as the Insular Islands approached North America. These islands sat on the Insular Plate. They moved toward the continental margin through the subduction of the Farallon Plate. This process occurred across the Bridge River Ocean, which was an ancient ocean basin.

This setup was unusual because it involved two parallel subduction zones. This is similar to the modern Philippine Mobile Belt near Asia. Eventually, the Bridge River Ocean closed as the plates moved closer together.

About 115 million years ago, the Insular Islands collided with the North American continental margin. This massive collision crushed, fractured, and folded the existing rocks. To weld these pieces together, huge amounts of magma cooled to create a large mass of igneous rock. This mass is actually the largest granite outcropping in North America. Following this, a new volcanic arc called the Coast Range Arc formed about 100 million years ago.

During this period, magma from the Farallon Plate rose through the new land. This magma injected massive quantities of granite into older rocks, creating the foundation of the mountains we see today.

Later geological events changed the shape and activity of the range. About 85 million years ago, a piece of the Farallon Plate called the Kula Plate broke off. This created the Kula-Farallon Ridge. This change triggered a period of mountain building known as the Laramide orogeny. During this time, intense heat and pressure transformed the rocks. Molten granite burned oceanic sediments into a glittering metamorphic rock called schist. Other rocks were turned into layered gneiss. In some areas, extreme stress created migmatite, which are rocks that look like they nearly melted.

Volcanic activity eventually declined as the plates moved. About 50 million years ago, volcanism along the Coast Range Arc shut down. This happened because the Kula Plate changed its direction of movement. Instead of sliding under the Pacific Northwest, it began moving under the Yukon and Alaska. Most of the original volcanoes have since been lost to erosion. Today, the mountains remain part of the Pacific Ring of Fire. This is a ring of volcanoes and mountains surrounding the Pacific Ocean. The range contains some of the highest peaks in British Columbia, including Mount Waddington. Mount Waddington is the highest peak in the range and the highest located entirely within British Columbia.