Denver to Seattle

An aerial view of Mount Rainier and Mount Adams breaking through the clouds. Many of the prominent Cascade peaks are formed by volcanoes, such as these.

A diagram showing the spreading ridges and subduction zones off the coast of North America, which generates the volcanic activity which produces volcanic peaks such as Mount St. Helens.

Mount Adams on a clear day, rising dramatically against the surrounding landscape. It is one of the Cascade Arc's largest volcanoes.

Coldwater Lake at the base of Mount St. Helens. The peak, lake and surrounding area was protected by being designated a National Volcanic Monument in 1982.

View of Mt. St. Helens from Johnston Ridge, red Indian Paintbrush regaining wasteland.

A map of the northern Cascades range, which stretches south from British Colombia in Canada to California in the United States, highlighting the major peaks.

A satellite image of Mount Hood, part of the Cascades range, showing its typical cone-shaped form with winding belts of lahars (mud flows) and debris from previous eruptions.

A NASA terrain map shows Mount Hood towering over the city of Portland below it, with the Colombia River flowing out of its gorge through the Cascades and into the city.

A satellite image showing some of the major volcanoes of the Cascade range: Mt. St. Helens, Mt. Hood, Mt. Rainier and Mt. Adams (as labelled).

Apple trees blooming along Mount Hood Scenic Byway with the majestic snow covered Mt. Hood in the background.

The Cascade range in Washington State: Elbow Peak (1,745m) can be seen in the centre with the snow-capped peak of Mount Rainier (4,392m) visible behind.

Views across the Cascades in central Washington State. The sharp mountains in the centre are the peaks near Snoqualmie Pass, and behind them Glacier Peak is also visible.

Trillium Lake, a peaceful mountain lake in Mount Hood National Forest reflecting Mt. Hood in the background.

A diagram detailing the major volcanoes of the Cascade range and marking their significant eruptions recorded over the last 4,000 years. Mount St. Helens is particularly active.

The majestic Mount Hood reflected in Mirror Lake at its base in Oregon. It is an active stratovolcano, with its striking white peak covered by 12 glaciers.

The sunset glows pink on a peak in the Northern Cascades. The range stretches from California into Canada.

A satellite image of Mount St. Helens, 20 years after the catastrophic 1980 eruption. Large ash and blast scars with broad lahar (landslide) trails can still be seen on the peak's flanks.

The dramatic eruption on May 18, 1980 blasted away 400 metres of Mount St. Helens' peak, with the blast damage covering over 650 square kilometres around the volcano.

Nearly 220 kilometres of river channels surrounding the volcano were affected by the lahars of May 18, 1980. A mudline left behind on trees shows depths reached by the mud.

Image 1, 1979: Mount St. Helens prior to the eruption. It is well contained with the surrounding area heavily vegetated (shown in red in this LANDSAT image).

Image 2, 1980: Mount St. Helens post eruption. The devastation caused by the huge blast and the following lahars can clearly be seen across the northern side of the volcano.

Image 3, 2009: Mount St. Helens 30 years on. Even after all of this time, much of the land to the north of the volcano (the Pumice Plain) lies barren, although life is slowly returning to the area.

The North Fork Toutle River valley shows part of the 2.3 cubic kilometres of debris avalanche that slid from the volcano on May 18, 1980, enough to cover Washington, D.C. to a depth of four meters.

More than 200 homes and over 300 kilometres of roads were destroyed by the 1980 lahars. This is a damaged home along the South Fork Toutle River, surrounded by blast debris and lahar.

The slopes of Smith Creek valley, east of Mount St. Helens, show trees blown down by the May 18, 1980 lateral blast (the blast is shown here as left to right). Two USGS scientists give scale.

For more than nine hours a vigorous plume of ash erupted, eventually reaching 20-25 kilometres above sea level. The plume moved eastward at an average speed of 95 km/hr.

Mount St. Helens is the smallest of five major volcanic peaks in Washington State, with an elevation of 2,950 meters before the eruption of May 18, 1980.

The USGS run both periodic and continuous monitoring programs at Mount St. Helens to study and predict eruptions. Here, geologists measure the distance across a crack on the crater floor.

Early in October 2004 Mt. St. Helens rumbled back to life with earthquakes, minor eruptions of steam and ash, and renewed growth of the summit lava dome.

A map of the area around Mount St. Helens which were affected by the May 18, 1980 eruption, detailing pyroclastic flows, mud flows and impact due to the blast and associated debris.

On March 20, 1980, after a quiet period of 123 years, earthquake activity once again began under Mount St. Helens volcano. Seven days later, on March 27, small steam explosions began.

Looking west from Mount St. Helens from space gives a clear idea of the huge regional impact of the blast zone, stretching clearly towards the top of the image over a huge area.

The car of a photographer who was killed whilst attempting to shoot the 1980 Mount St. Helens eruption is engulfed by a mud flow about 15 kilometres from the volcano.

An aerial view of Mount Rainier poking through the clouds. The peak is obscured by another lenticular cloud formed over its summit, but glaciers on the flanks can clearly be seen.

A spring view of Mount Rainier looking north towards the summit from Mertle Falls. The Lushootseed tribes believed that the mountain was the "mother of waters".

An aerial view looking up the Cascades Mountains towards Mount Rainier. Easily visible from Seattle on a clear day, the peak of the mountain is often obscured by cloud.

Mount Rainier, the highest peak in the Cascade range. The volcano overlooks the 2.5 million people in the Seattle area and is thought to be one of the most dangerous in the world.

Mount Rainier towers over nearby Tacoma, Washington which is named for the Lushootseed term for the mountain, Tahoma.

An eruption hazard map covering Mount Rainier and the surrounding areas, highlighting the ranges of risks from lahars (red and orange), lava flows (grey) and mudflows (yellow).

Mount Rainier with its main summit, Columbia Crest (4,392 metres) at the centre. Emmons Glacier covers most of the visible flank of the mountain.

Well signed evacuation routes give advice for residents and tourists in case of eruption at Mount Rainier, which is likely to cause very large and fast-flowing lahars to course down the mountain.

The three summits of Mount Rainier: From left to right, the high points are Liberty Cap, Columbia Crest (the summit proper), and Point Success. Tahoma Glacier descends to the lower right.

Climbers attempting to summit Columbia Crest on Mount Rainier, on Ingraham Glacier looking down towards the jagged peak of Little Tahoma breaking through the clouds.

1790 - Mount Rainier from: "A Voyage of Discovery to the North Pacific Ocean and Round the World" by Captain George Vancouver, the first European to see the mountain.

Mount Rainier as viewed from Reflection Lake. The largest peak in the Cascades, it rises 4,392 metres above sea level and although looks serene is still an active volcano.

Colombia Crest with the climber's route to the summit visible in the centre of the image. Climbing the peak is dangerous due to the large number of crevasses, clearly seen in this image.